51999957 has 24 divisors (see below), whose sum is σ = 80098200. Its totient is φ = 32394240.

The previous prime is 51999919. The next prime is 51999971. The reversal of 51999957 is 75999915.

It can be written as a sum of positive squares in 4 ways, for example, as 6922161 + 45077796 = 2631^2 + 6714^2 .

It is not a de Polignac number, because 51999957 - 2¹¹ = 51997909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51991957) 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, 21657 + ... + 23937.

It is an arithmetic number, because the mean of its divisors is an integer number (3337425).

Almost surely, 2^51999957 is an apocalyptic number.

It is an amenable number.

51999957 is a deficient number, since it is larger than the sum of its proper divisors (28098243).

51999957 is a wasteful number, since it uses less digits than its factorization.

51999957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2453 (or 2450 counting only the distinct ones).

The product of its digits is 1148175, while the sum is 54.

The square root of 51999957 is about 7211.0995694138. The cubic root of 51999957 is about 373.2510127984.

The spelling of 51999957 in words is "fifty-one million, nine hundred ninety-nine thousand, nine hundred fifty-seven".