221618990089728 has 1920 divisors, whose sum is σ = 839508324695040. Its totient is φ = 57201002496000.

The previous prime is 221618990089727. The next prime is 221618990089729. The reversal of 221618990089728 is 827980099816122.

221618990089728 is a `hidden beast` number, since 2 + 216 + 189 + 90 + 0 + 89 + 72 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (221618990089727) and next prime (221618990089729).

It is a super-2 number, since 2×221618990089728² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221618990089727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 171664592763 + ... + 171664594053.

It is an arithmetic number, because the mean of its divisors is an integer number (437243919112).

Almost surely, 2^{221618990089728} is an apocalyptic number.

221618990089728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221618990089728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (419754162347520).

221618990089728 is an abundant number, since it is smaller than the sum of its proper divisors (617889334605312).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221618990089728 is an equidigital number, since it uses as much as digits as its factorization.

221618990089728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1540 (or 1495 counting only the distinct ones).

The product of its (nonzero) digits is 125411328, while the sum is 72.

The spelling of 221618990089728 in words is "two hundred twenty-one trillion, six hundred eighteen billion, nine hundred ninety million, eighty-nine thousand, seven hundred twenty-eight".