51987117 has 32 divisors (see below), whose sum is σ = 86946048. Its totient is φ = 26896896.

The previous prime is 51987113. The next prime is 51987121. The reversal of 51987117 is 71178915.

It is an interprime number because it is at equal distance from previous prime (51987113) and next prime (51987121).

It is not a de Polignac number, because 51987117 - 2² = 51987113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51987113) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12673 + ... + 16265.

It is an arithmetic number, because the mean of its divisors is an integer number (2717064).

Almost surely, 2^51987117 is an apocalyptic number.

It is an amenable number.

51987117 is a deficient number, since it is larger than the sum of its proper divisors (34958931).

51987117 is a wasteful number, since it uses less digits than its factorization.

51987117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3669.

The product of its digits is 17640, while the sum is 39.

The square root of 51987117 is about 7210.2092202654. The cubic root of 51987117 is about 373.2202888145.

The spelling of 51987117 in words is "fifty-one million, nine hundred eighty-seven thousand, one hundred seventeen".