9216621596538 has 12 divisors (see below), whose sum is σ = 19969346792538. Its totient is φ = 3072207198840.

The previous prime is 9216621596531. The next prime is 9216621596569. The reversal of 9216621596538 is 8356951266129.

9216621596538 is a `hidden beast` number, since 9 + 2 + 1 + 6 + 6 + 2 + 1 + 5 + 96 + 538 = 666.

It can be written as a sum of positive squares in only one way, i.e., 9134400048489 + 82221548049 = 3022317^2 + 286743^2 .

It is a super-2 number, since 2×9216621596538² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9216621596531) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 256017266553 + ... + 256017266588.

Almost surely, 2^{9216621596538} is an apocalyptic number.

9216621596538 is an abundant number, since it is smaller than the sum of its proper divisors (10752725196000).

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

9216621596538 is a wasteful number, since it uses less digits than its factorization.

9216621596538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512034533149 (or 512034533146 counting only the distinct ones).

The product of its digits is 41990400, while the sum is 63.

The spelling of 9216621596538 in words is "nine trillion, two hundred sixteen billion, six hundred twenty-one million, five hundred ninety-six thousand, five hundred thirty-eight".