20970657 has 24 divisors (see below), whose sum is σ = 31638880. Its totient is φ = 13880160.

The previous prime is 20970643. The next prime is 20970667. The reversal of 20970657 is 75607902.

It is not a de Polignac number, because 20970657 - 2¹⁹ = 20446369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20970617) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51069 + ... + 51477.

Almost surely, 2^20970657 is an apocalyptic number.

20970657 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20970657 is a deficient number, since it is larger than the sum of its proper divisors (10668223).

20970657 is an equidigital number, since it uses as much as digits as its factorization.

20970657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 36.

The square root of 20970657 is about 4579.3729920154. The cubic root of 20970657 is about 275.7638575632.

The spelling of 20970657 in words is "twenty million, nine hundred seventy thousand, six hundred fifty-seven".