21253813376 has 32 divisors (see below), whose sum is σ = 42379373100. Its totient is φ = 10617421824.

The previous prime is 21253813363. The next prime is 21253813379. The reversal of 21253813376 is 67331835212.

It can be written as a sum of positive squares in 2 ways, for example, as 16848040000 + 4405773376 = 129800^2 + 66376^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (21253813379) 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, 70976 + ... + 218048.

Almost surely, 2^21253813376 is an apocalyptic number.

It is an amenable number.

21253813376 is a deficient number, since it is larger than the sum of its proper divisors (21125559724).

21253813376 is a wasteful number, since it uses less digits than its factorization.

21253813376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148216 (or 148204 counting only the distinct ones).

The product of its digits is 181440, while the sum is 41.

The spelling of 21253813376 in words is "twenty-one billion, two hundred fifty-three million, eight hundred thirteen thousand, three hundred seventy-six".