51531756 has 12 divisors (see below), whose sum is σ = 120240792. Its totient is φ = 17177248.

The previous prime is 51531749. The next prime is 51531757. The reversal of 51531756 is 65713515.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (51531757) 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, 2147145 + ... + 2147168.

It is an arithmetic number, because the mean of its divisors is an integer number (10020066).

Almost surely, 2^51531756 is an apocalyptic number.

It is an amenable number.

51531756 is an abundant number, since it is smaller than the sum of its proper divisors (68709036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51531756 is a wasteful number, since it uses less digits than its factorization.

51531756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4294320 (or 4294318 counting only the distinct ones).

The product of its digits is 15750, while the sum is 33.

The square root of 51531756 is about 7178.5622515933. The cubic root of 51531756 is about 372.1273988436.

The spelling of 51531756 in words is "fifty-one million, five hundred thirty-one thousand, seven hundred fifty-six".