51957421 has 4 divisors (see below), whose sum is σ = 52809244. Its totient is φ = 51105600.

The previous prime is 51957413. The next prime is 51957427. The reversal of 51957421 is 12475915.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11634921 + 40322500 = 3411^2 + 6350^2 .

It is a cyclic number.

It is not a de Polignac number, because 51957421 - 2³ = 51957413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51957427) 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, 425820 + ... + 425941.

It is an arithmetic number, because the mean of its divisors is an integer number (13202311).

Almost surely, 2^51957421 is an apocalyptic number.

It is an amenable number.

51957421 is a deficient number, since it is larger than the sum of its proper divisors (851823).

51957421 is an equidigital number, since it uses as much as digits as its factorization.

51957421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851822.

The product of its digits is 12600, while the sum is 34.

The square root of 51957421 is about 7208.1496238633. The cubic root of 51957421 is about 373.1492118419.

The spelling of 51957421 in words is "fifty-one million, nine hundred fifty-seven thousand, four hundred twenty-one".