221746731687936 has 3360 divisors, whose sum is σ = 881729165826432. Its totient is φ = 54059209850880.

The previous prime is 221746731687913. The next prime is 221746731687937. The reversal of 221746731687936 is 639786137647122.

221746731687936 is a `hidden beast` number, since 2 + 2 + 1 + 7 + 467 + 3 + 1 + 68 + 79 + 36 = 666.

It is a super-2 number, since 2×221746731687936² (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 nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221746731687937) 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 239 ways as a sum of consecutive naturals, for example, 1692723142591 + ... + 1692723142721.

Almost surely, 2^{221746731687936} is an apocalyptic number.

221746731687936 is a gapful number since it is divisible by the number (26) 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 221746731687936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (440864582913216).

221746731687936 is an abundant number, since it is smaller than the sum of its proper divisors (659982434138496).

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

221746731687936 is a wasteful number, since it uses less digits than its factorization.

221746731687936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320 (or 270 counting only the distinct ones).

The product of its digits is 768144384, while the sum is 72.

The spelling of 221746731687936 in words is "two hundred twenty-one trillion, seven hundred forty-six billion, seven hundred thirty-one million, six hundred eighty-seven thousand, nine hundred thirty-six".