51531904 has 16 divisors (see below), whose sum is σ = 102661470. Its totient is φ = 25765888.

The previous prime is 51531899. The next prime is 51531919. The reversal of 51531904 is 40913515.

It can be written as a sum of positive squares in only one way, i.e., 37454400 + 14077504 = 6120^2 + 3752^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-3 number, since 3×51531904³ (a number of 24 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201169 + ... + 201424.

Almost surely, 2^51531904 is an apocalyptic number.

It is an amenable number.

51531904 is a deficient number, since it is larger than the sum of its proper divisors (51129566).

51531904 is an equidigital number, since it uses as much as digits as its factorization.

51531904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402607 (or 402595 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 51531904 is about 7178.5725600568. The cubic root of 51531904 is about 372.1277550952.

The spelling of 51531904 in words is "fifty-one million, five hundred thirty-one thousand, nine hundred four".