20901657 has 32 divisors (see below), whose sum is σ = 33316864. Its totient is φ = 11404800.

The previous prime is 20901637. The next prime is 20901667. The reversal of 20901657 is 75610902.

It is not a de Polignac number, because 20901657 - 2⁸ = 20901401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20901607) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62982 + ... + 63312.

It is an arithmetic number, because the mean of its divisors is an integer number (1041152).

Almost surely, 2^20901657 is an apocalyptic number.

It is an amenable number.

20901657 is a deficient number, since it is larger than the sum of its proper divisors (12415207).

20901657 is a wasteful number, since it uses less digits than its factorization.

20901657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469.

The product of its (nonzero) digits is 3780, while the sum is 30.

The square root of 20901657 is about 4571.8330021994. The cubic root of 20901657 is about 275.4610755468.

The spelling of 20901657 in words is "twenty million, nine hundred one thousand, six hundred fifty-seven".