51631551 has 6 divisors (see below), whose sum is σ = 74578920. Its totient is φ = 34421028.

The previous prime is 51631543. The next prime is 51631577. The reversal of 51631551 is 15513615.

51631551 is a `hidden beast` number, since 51 + 63 + 1 + 551 = 666.

It is not a de Polignac number, because 51631551 - 2³ = 51631543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51631501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2868411 + ... + 2868428.

It is an arithmetic number, because the mean of its divisors is an integer number (12429820).

Almost surely, 2^51631551 is an apocalyptic number.

51631551 is a deficient number, since it is larger than the sum of its proper divisors (22947369).

51631551 is a wasteful number, since it uses less digits than its factorization.

51631551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5736845 (or 5736842 counting only the distinct ones).

The product of its digits is 2250, while the sum is 27.

The square root of 51631551 is about 7185.5097940230. The cubic root of 51631551 is about 372.3674612176.

The spelling of 51631551 in words is "fifty-one million, six hundred thirty-one thousand, five hundred fifty-one".