20916172 has 6 divisors (see below), whose sum is σ = 36603308. Its totient is φ = 10458084.

The previous prime is 20916151. The next prime is 20916197. The reversal of 20916172 is 27161902.

It is a happy number.

20916172 is nontrivially palindromic in base 13.

It is a super-2 number, since 2×20916172² = 874972502267168, which contains 22 as substring.

20916172 is a nontrivial repdigit in base 13.

It is a plaindrome in base 13.

It is a nialpdrome in base 13.

It is a zygodrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 20916172.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2614518 + ... + 2614525.

Almost surely, 2^20916172 is an apocalyptic number.

It is an amenable number.

20916172 is a deficient number, since it is larger than the sum of its proper divisors (15687136).

20916172 is a wasteful number, since it uses less digits than its factorization.

20916172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5229047 (or 5229045 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 20916172 is about 4573.4201643846. The cubic root of 20916172 is about 275.5248247563.

The spelling of 20916172 in words is "twenty million, nine hundred sixteen thousand, one hundred seventy-two".