51688657 has 2 divisors, whose sum is σ = 51688658. Its totient is φ = 51688656.

The previous prime is 51688649. The next prime is 51688697. The reversal of 51688657 is 75688615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49617936 + 2070721 = 7044^2 + 1439^2 .

It is a cyclic number.

It is not a de Polignac number, because 51688657 - 2³ = 51688649 is a prime.

It is not a weakly prime, because it can be changed into another prime (51688627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25844328 + 25844329.

It is an arithmetic number, because the mean of its divisors is an integer number (25844329).

Almost surely, 2^51688657 is an apocalyptic number.

It is an amenable number.

51688657 is a deficient number, since it is larger than the sum of its proper divisors (1).

51688657 is an equidigital number, since it uses as much as digits as its factorization.

51688657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 403200, while the sum is 46.

The square root of 51688657 is about 7189.4823874880. The cubic root of 51688657 is about 372.5046937234.

The spelling of 51688657 in words is "fifty-one million, six hundred eighty-eight thousand, six hundred fifty-seven".