21146553265640 has 64 divisors (see below), whose sum is σ = 51921048021120. Its totient is φ = 7687304352000.

The previous prime is 21146553265633. The next prime is 21146553265723. The reversal of 21146553265640 is 4656235564112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5907191 + ... + 8785670.

It is an arithmetic number, because the mean of its divisors is an integer number (811266375330).

Almost surely, 2^{21146553265640} is an apocalyptic number.

21146553265640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21146553265640 is an abundant number, since it is smaller than the sum of its proper divisors (30774494755480).

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

21146553265640 is a wasteful number, since it uses less digits than its factorization.

21146553265640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14696154 (or 14696150 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 50.

The spelling of 21146553265640 in words is "twenty-one trillion, one hundred forty-six billion, five hundred fifty-three million, two hundred sixty-five thousand, six hundred forty".