21616052005256 has 32 divisors (see below), whose sum is σ = 41666389805880. Its totient is φ = 10506890956800.

The previous prime is 21616052005253. The next prime is 21616052005291. The reversal of 21616052005256 is 65250025061612.

It can be written as a sum of positive squares in 4 ways, for example, as 13071363008356 + 8544688996900 = 3615434^2 + 2923130^2 .

It is a Harshad number since it is a multiple of its sum of digits (41).

It is not an unprimeable number, because it can be changed into a prime (21616052005253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117172241 + ... + 117356576.

Almost surely, 2^{21616052005256} is an apocalyptic number.

It is an amenable number.

21616052005256 is a deficient number, since it is larger than the sum of its proper divisors (20050337800624).

21616052005256 is a wasteful number, since it uses less digits than its factorization.

21616052005256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234529145 (or 234529141 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 41.

Adding to 21616052005256 its reverse (65250025061612), we get a palindrome (86866077066868).

The spelling of 21616052005256 in words is "twenty-one trillion, six hundred sixteen billion, fifty-two million, five thousand, two hundred fifty-six".