51551531 has 12 divisors (see below), whose sum is σ = 56659920. Its totient is φ = 46838400.

The previous prime is 51551509. The next prime is 51551537. The reversal of 51551531 is 13515515.

51551531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51551531 - 2¹⁸ = 51289387 is a prime.

It is a super-2 number, since 2×51551531² = 5315120696887922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51551531.

It is not an unprimeable number, because it can be changed into a prime (51551537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5306 + ... + 11456.

It is an arithmetic number, because the mean of its divisors is an integer number (4721660).

Almost surely, 2^51551531 is an apocalyptic number.

51551531 is a deficient number, since it is larger than the sum of its proper divisors (5108389).

51551531 is a wasteful number, since it uses less digits than its factorization.

51551531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6214 (or 6197 counting only the distinct ones).

The product of its digits is 1875, while the sum is 26.

The square root of 51551531 is about 7179.9394844246. The cubic root of 51551531 is about 372.1749933031.

The spelling of 51551531 in words is "fifty-one million, five hundred fifty-one thousand, five hundred thirty-one".