20957393 has 12 divisors (see below), whose sum is σ = 22131060. Its totient is φ = 19843296.

The previous prime is 20957371. The next prime is 20957407. The reversal of 20957393 is 39375902.

It can be written as a sum of positive squares in 2 ways, for example, as 19298449 + 1658944 = 4393^2 + 1288^2 .

It is not a de Polignac number, because 20957393 - 2⁶ = 20957329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20957303) 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, 91403 + ... + 91631.

It is an arithmetic number, because the mean of its divisors is an integer number (1844255).

Almost surely, 2^20957393 is an apocalyptic number.

20957393 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

20957393 is a deficient number, since it is larger than the sum of its proper divisors (1173667).

20957393 is a wasteful number, since it uses less digits than its factorization.

20957393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448 (or 425 counting only the distinct ones).

The product of its (nonzero) digits is 51030, while the sum is 38.

The square root of 20957393 is about 4577.9245297405. The cubic root of 20957393 is about 275.7057048270.

The spelling of 20957393 in words is "twenty million, nine hundred fifty-seven thousand, three hundred ninety-three".