221550819840 has 640 divisors, whose sum is σ = 928466288640. Its totient is φ = 49003315200.

The previous prime is 221550819829. The next prime is 221550819859. The reversal of 221550819840 is 48918055122.

221550819840 is a `hidden beast` number, since 2 + 2 + 1 + 550 + 8 + 1 + 98 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a super-2 number, since 2×221550819840² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14991655 + ... + 15006425.

It is an arithmetic number, because the mean of its divisors is an integer number (1450728576).

Almost surely, 2^221550819840 is an apocalyptic number.

221550819840 is a gapful number since it is divisible by the number (20) 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 221550819840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (464233144320).

221550819840 is an abundant number, since it is smaller than the sum of its proper divisors (706915468800).

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

221550819840 is a wasteful number, since it uses less digits than its factorization.

221550819840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14841 (or 14819 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

The spelling of 221550819840 in words is "two hundred twenty-one billion, five hundred fifty million, eight hundred nineteen thousand, eight hundred forty".