20957249 has 4 divisors (see below), whose sum is σ = 21117360. Its totient is φ = 20797140.

The previous prime is 20957239. The next prime is 20957263. The reversal of 20957249 is 94275902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20957249 - 2⁸ = 20956993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20957219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79859 + ... + 80120.

It is an arithmetic number, because the mean of its divisors is an integer number (5279340).

Almost surely, 2^20957249 is an apocalyptic number.

It is an amenable number.

20957249 is a deficient number, since it is larger than the sum of its proper divisors (160111).

20957249 is a wasteful number, since it uses less digits than its factorization.

20957249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160110.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 20957249 is about 4577.9088020624. The cubic root of 20957249 is about 275.7050733599.

The spelling of 20957249 in words is "twenty million, nine hundred fifty-seven thousand, two hundred forty-nine".