51521751 has 10 divisors (see below), whose sum is σ = 76964712. Its totient is φ = 34347780.

The previous prime is 51521737. The next prime is 51521753. The reversal of 51521751 is 15712515.

It is not a de Polignac number, because 51521751 - 2⁷ = 51521623 is a prime.

It is a super-2 number, since 2×51521751² = 5308981652212002, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51521753) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 317955 + ... + 318116.

Almost surely, 2^51521751 is an apocalyptic number.

51521751 is a deficient number, since it is larger than the sum of its proper divisors (25442961).

51521751 is an equidigital number, since it uses as much as digits as its factorization.

51521751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636083 (or 636074 counting only the distinct ones).

The product of its digits is 1750, while the sum is 27.

The square root of 51521751 is about 7177.8653512030. The cubic root of 51521751 is about 372.1033141763.

It can be divided in two parts, 5152 and 1751, that added together give a triangular number (6903 = T₁₁₇).

The spelling of 51521751 in words is "fifty-one million, five hundred twenty-one thousand, seven hundred fifty-one".