20970665 has 16 divisors (see below), whose sum is σ = 25997760. Its totient is φ = 16230720.

The previous prime is 20970643. The next prime is 20970667. The reversal of 20970665 is 56607902.

It is a de Polignac number, because none of the positive numbers 2^k-20970665 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20970667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19235 + ... + 20295.

It is an arithmetic number, because the mean of its divisors is an integer number (1624860).

Almost surely, 2^20970665 is an apocalyptic number.

It is an amenable number.

20970665 is a deficient number, since it is larger than the sum of its proper divisors (5027095).

20970665 is a wasteful number, since it uses less digits than its factorization.

20970665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1192.

The product of its (nonzero) digits is 22680, while the sum is 35.

The square root of 20970665 is about 4579.3738654973. The cubic root of 20970665 is about 275.7638926298.

The spelling of 20970665 in words is "twenty million, nine hundred seventy thousand, six hundred sixty-five".