20972690 has 32 divisors (see below), whose sum is σ = 38776320. Its totient is φ = 8164800.

The previous prime is 20972663. The next prime is 20972729. The reversal of 20972690 is 9627902.

It is a super-2 number, since 2×20972690² = 879707451672200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20972690.

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, 77255 + ... + 77525.

It is an arithmetic number, because the mean of its divisors is an integer number (1211760).

Almost surely, 2^20972690 is an apocalyptic number.

20972690 is a deficient number, since it is larger than the sum of its proper divisors (17803630).

20972690 is a wasteful number, since it uses less digits than its factorization.

20972690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 20972690 is about 4579.5949602558. The cubic root of 20972690 is about 275.7727685828.

The spelling of 20972690 in words is "twenty million, nine hundred seventy-two thousand, six hundred ninety".