51251515 has 16 divisors (see below), whose sum is σ = 74423232. Its totient is φ = 33076224.

The previous prime is 51251491. The next prime is 51251527. The reversal of 51251515 is 51515215.

It is a cyclic number.

It is not a de Polignac number, because 51251515 - 2¹⁹ = 50727227 is a prime.

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 51251515.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42474 + ... + 43663.

It is an arithmetic number, because the mean of its divisors is an integer number (4651452).

Almost surely, 2^51251515 is an apocalyptic number.

51251515 is a deficient number, since it is larger than the sum of its proper divisors (23171717).

51251515 is a wasteful number, since it uses less digits than its factorization.

51251515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86166.

The product of its digits is 1250, while the sum is 25.

The square root of 51251515 is about 7159.0163430460. The cubic root of 51251515 is about 371.4516021574.

The spelling of 51251515 in words is "fifty-one million, two hundred fifty-one thousand, five hundred fifteen".