51131604 has 12 divisors (see below), whose sum is σ = 119307104. Its totient is φ = 17043864.

The previous prime is 51131593. The next prime is 51131621. The reversal of 51131604 is 40613115.

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

It is a super-2 number, since 2×51131604² = 5228881855225632, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2130472 + ... + 2130495.

Almost surely, 2^51131604 is an apocalyptic number.

It is an amenable number.

51131604 is an abundant number, since it is smaller than the sum of its proper divisors (68175500).

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

51131604 is a wasteful number, since it uses less digits than its factorization.

51131604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4260974 (or 4260972 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 51131604 is about 7150.6366150155. The cubic root of 51131604 is about 371.1616860754.

Adding to 51131604 its reverse (40613115), we get a palindrome (91744719).

The spelling of 51131604 in words is "fifty-one million, one hundred thirty-one thousand, six hundred four".