20646875 has 12 divisors (see below), whose sum is σ = 25810848. Its totient is φ = 16515000.

The previous prime is 20646841. The next prime is 20646877. The reversal of 20646875 is 57864602.

It is a happy number.

It is not a de Polignac number, because 20646875 - 2¹⁸ = 20384731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20646877) 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, 179 + ... + 6428.

It is an arithmetic number, because the mean of its divisors is an integer number (2150904).

Almost surely, 2^20646875 is an apocalyptic number.

20646875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20646875 is a deficient number, since it is larger than the sum of its proper divisors (5163973).

20646875 is an frugal number, since it uses more digits than its factorization.

20646875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6632 (or 6612 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 20646875 is about 4543.8832511410. The cubic root of 20646875 is about 274.3372470164.

The spelling of 20646875 in words is "twenty million, six hundred forty-six thousand, eight hundred seventy-five".