16636252921 has 12 divisors (see below), whose sum is σ = 18602554480. Its totient is φ = 14833558080.

The previous prime is 16636252903. The next prime is 16636252931. The reversal of 16636252921 is 12925263661.

It is a de Polignac number, because none of the positive numbers 2^k-16636252921 is a prime.

It is a super-2 number, since 2×16636252921² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16636252931) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1509375 + ... + 1520356.

Almost surely, 2^16636252921 is an apocalyptic number.

It is an amenable number.

16636252921 is a deficient number, since it is larger than the sum of its proper divisors (1966301559).

16636252921 is a wasteful number, since it uses less digits than its factorization.

16636252921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3029784 (or 3029767 counting only the distinct ones).

The product of its digits is 233280, while the sum is 43.

The spelling of 16636252921 in words is "sixteen billion, six hundred thirty-six million, two hundred fifty-two thousand, nine hundred twenty-one".