51566815 has 4 divisors (see below), whose sum is σ = 61880184. Its totient is φ = 41253448.

The previous prime is 51566813. The next prime is 51566869. The reversal of 51566815 is 51866515.

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

It is a cyclic number.

It is not a de Polignac number, because 51566815 - 2¹ = 51566813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51566813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5156677 + ... + 5156686.

It is an arithmetic number, because the mean of its divisors is an integer number (15470046).

Almost surely, 2^51566815 is an apocalyptic number.

51566815 is a deficient number, since it is larger than the sum of its proper divisors (10313369).

51566815 is a wasteful number, since it uses less digits than its factorization.

51566815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10313368.

The product of its digits is 36000, while the sum is 37.

The square root of 51566815 is about 7181.0037599210. The cubic root of 51566815 is about 372.2117704878.

The spelling of 51566815 in words is "fifty-one million, five hundred sixty-six thousand, eight hundred fifteen".