21017497332808 has 16 divisors (see below), whose sum is σ = 39461133366000. Its totient is φ = 10494528435216.

The previous prime is 21017497332781. The next prime is 21017497332809. The reversal of 21017497332808 is 80823379471012.

It is not an unprimeable number, because it can be changed into a prime (21017497332809) 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, 1777522618 + ... + 1777534441.

It is an arithmetic number, because the mean of its divisors is an integer number (2466320835375).

Almost surely, 2^{21017497332808} is an apocalyptic number.

It is an amenable number.

21017497332808 is a deficient number, since it is larger than the sum of its proper divisors (18443636033192).

21017497332808 is a wasteful number, since it uses less digits than its factorization.

21017497332808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3555057804 (or 3555057800 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 55.

The spelling of 21017497332808 in words is "twenty-one trillion, seventeen billion, four hundred ninety-seven million, three hundred thirty-two thousand, eight hundred eight".