21104002256 has 20 divisors (see below), whose sum is σ = 40902202404. Its totient is φ = 10548595200.

The previous prime is 21104002253. The next prime is 21104002267. The reversal of 21104002256 is 65220040112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 10462016656 + 10641985600 = 102284^2 + 103160^2 .

It is a super-2 number, since 2×21104002256² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21104002253) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161375 + ... + 261246.

Almost surely, 2^21104002256 is an apocalyptic number.

It is an amenable number.

21104002256 is a deficient number, since it is larger than the sum of its proper divisors (19798200148).

21104002256 is a wasteful number, since it uses less digits than its factorization.

21104002256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425750 (or 425744 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21104002256 its reverse (65220040112), we get a palindrome (86324042368).

The spelling of 21104002256 in words is "twenty-one billion, one hundred four million, two thousand, two hundred fifty-six".