51864857 has 4 divisors (see below), whose sum is σ = 56579856. Its totient is φ = 47149860.

The previous prime is 51864817. The next prime is 51864871. The reversal of 51864857 is 75846815.

It is a happy number.

51864857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51864857 - 2²⁴ = 35087641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51864817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2357483 + ... + 2357504.

It is an arithmetic number, because the mean of its divisors is an integer number (14144964).

Almost surely, 2^51864857 is an apocalyptic number.

It is an amenable number.

51864857 is a deficient number, since it is larger than the sum of its proper divisors (4714999).

51864857 is a wasteful number, since it uses less digits than its factorization.

51864857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4714998.

The product of its digits is 268800, while the sum is 44.

The square root of 51864857 is about 7201.7259736816. The cubic root of 51864857 is about 372.9274872398.

The spelling of 51864857 in words is "fifty-one million, eight hundred sixty-four thousand, eight hundred fifty-seven".