20853657 has 12 divisors (see below), whose sum is σ = 32860464. Its totient is φ = 12638520.

The previous prime is 20853649. The next prime is 20853661. The reversal of 20853657 is 75635802.

It is not a de Polignac number, because 20853657 - 2³ = 20853649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20853257) 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, 105223 + ... + 105420.

It is an arithmetic number, because the mean of its divisors is an integer number (2738372).

Almost surely, 2^20853657 is an apocalyptic number.

It is an amenable number.

20853657 is a deficient number, since it is larger than the sum of its proper divisors (12006807).

20853657 is a wasteful number, since it uses less digits than its factorization.

20853657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210660 (or 210657 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 20853657 is about 4566.5804493078. The cubic root of 20853657 is about 275.2500513529.

The spelling of 20853657 in words is "twenty million, eight hundred fifty-three thousand, six hundred fifty-seven".