20955857 has 8 divisors (see below), whose sum is σ = 22604736. Its totient is φ = 19312272.

The previous prime is 20955853. The next prime is 20955871. The reversal of 20955857 is 75855902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20955857 - 2² = 20955853 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20955853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11738 + ... + 13404.

It is an arithmetic number, because the mean of its divisors is an integer number (2825592).

Almost surely, 2^20955857 is an apocalyptic number.

It is an amenable number.

20955857 is a deficient number, since it is larger than the sum of its proper divisors (1648879).

20955857 is a wasteful number, since it uses less digits than its factorization.

20955857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2647.

The product of its (nonzero) digits is 126000, while the sum is 41.

The square root of 20955857 is about 4577.7567650543. The cubic root of 20955857 is about 275.6989690288.

It can be divided in two parts, 20955 and 857, that added together give a palindrome (21812).

The spelling of 20955857 in words is "twenty million, nine hundred fifty-five thousand, eight hundred fifty-seven".