20646407 has 16 divisors (see below), whose sum is σ = 22872960. Its totient is φ = 18561312.

The previous prime is 20646361. The next prime is 20646421. The reversal of 20646407 is 70464602.

It is a cyclic number.

It is not a de Polignac number, because 20646407 - 2⁸ = 20646151 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20646407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20646467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29888 + ... + 30570.

It is an arithmetic number, because the mean of its divisors is an integer number (1429560).

Almost surely, 2^20646407 is an apocalyptic number.

20646407 is a deficient number, since it is larger than the sum of its proper divisors (2226553).

20646407 is a wasteful number, since it uses less digits than its factorization.

20646407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 782.

The product of its (nonzero) digits is 8064, while the sum is 29.

The square root of 20646407 is about 4543.8317530472. The cubic root of 20646407 is about 274.3351742120.

The spelling of 20646407 in words is "twenty million, six hundred forty-six thousand, four hundred seven".