51012865 has 4 divisors (see below), whose sum is σ = 61215444. Its totient is φ = 40810288.

The previous prime is 51012851. The next prime is 51012883. The reversal of 51012865 is 56821015.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 31854736 + 19158129 = 5644^2 + 4377^2 .

It is a cyclic number.

It is not a de Polignac number, because 51012865 - 2²⁵ = 17458433 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5101282 + ... + 5101291.

It is an arithmetic number, because the mean of its divisors is an integer number (15303861).

Almost surely, 2^51012865 is an apocalyptic number.

It is an amenable number.

51012865 is a deficient number, since it is larger than the sum of its proper divisors (10202579).

51012865 is a wasteful number, since it uses less digits than its factorization.

51012865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10202578.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 51012865 is about 7142.3291019107. The cubic root of 51012865 is about 370.8741566246.

The spelling of 51012865 in words is "fifty-one million, twelve thousand, eight hundred sixty-five".