21035645956 has 12 divisors (see below), whose sum is σ = 39644102092. Its totient is φ = 9708759648.

The previous prime is 21035645951. The next prime is 21035645977. The reversal of 21035645956 is 65954653012.

It can be written as a sum of positive squares in 2 ways, for example, as 6986285056 + 14049360900 = 83584^2 + 118530^2 .

It is not an unprimeable number, because it can be changed into a prime (21035645951) 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, 202265775 + ... + 202265878.

Almost surely, 2^21035645956 is an apocalyptic number.

21035645956 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21035645956 is a deficient number, since it is larger than the sum of its proper divisors (18608456136).

21035645956 is a wasteful number, since it uses less digits than its factorization.

21035645956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404531670 (or 404531668 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 46.

The spelling of 21035645956 in words is "twenty-one billion, thirty-five million, six hundred forty-five thousand, nine hundred fifty-six".