20451957 has 4 divisors (see below), whose sum is σ = 27269280. Its totient is φ = 13634636.

The previous prime is 20451941. The next prime is 20451967. The reversal of 20451957 is 75915402.

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 20451957 - 2⁴ = 20451941 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20451917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3408657 + ... + 3408662.

It is an arithmetic number, because the mean of its divisors is an integer number (6817320).

Almost surely, 2^20451957 is an apocalyptic number.

It is an amenable number.

20451957 is a deficient number, since it is larger than the sum of its proper divisors (6817323).

20451957 is an equidigital number, since it uses as much as digits as its factorization.

20451957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6817322.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 20451957 is about 4522.3839951955. The cubic root of 20451957 is about 273.4712171995.

The spelling of 20451957 in words is "twenty million, four hundred fifty-one thousand, nine hundred fifty-seven".