20644955 has 16 divisors (see below), whose sum is σ = 25807680. Its totient is φ = 15835008.

The previous prime is 20644909. The next prime is 20644973. The reversal of 20644955 is 55944602.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20644955 - 2⁸ = 20644699 is a prime.

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, 24674 + ... + 25496.

It is an arithmetic number, because the mean of its divisors is an integer number (1612980).

Almost surely, 2^20644955 is an apocalyptic number.

20644955 is a deficient number, since it is larger than the sum of its proper divisors (5162725).

20644955 is a wasteful number, since it uses less digits than its factorization.

20644955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 20644955 is about 4543.6719731952. The cubic root of 20644955 is about 274.3287430041.

The spelling of 20644955 in words is "twenty million, six hundred forty-four thousand, nine hundred fifty-five".