51686855 has 16 divisors (see below), whose sum is σ = 69316128. Its totient is φ = 36672000.

The previous prime is 51686849. The next prime is 51686863. The reversal of 51686855 is 55868615.

It is not a de Polignac number, because 51686855 - 2¹⁶ = 51621319 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 9206 + ... + 13715.

It is an arithmetic number, because the mean of its divisors is an integer number (4332258).

Almost surely, 2^51686855 is an apocalyptic number.

51686855 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

51686855 is a deficient number, since it is larger than the sum of its proper divisors (17629273).

51686855 is a wasteful number, since it uses less digits than its factorization.

51686855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22978.

The product of its digits is 288000, while the sum is 44.

The square root of 51686855 is about 7189.3570644391. The cubic root of 51686855 is about 372.5003648481.

The spelling of 51686855 in words is "fifty-one million, six hundred eighty-six thousand, eight hundred fifty-five".