51668657 has 4 divisors (see below), whose sum is σ = 54388080. Its totient is φ = 48949236.

The previous prime is 51668621. The next prime is 51668677. The reversal of 51668657 is 75686615.

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 a de Polignac number, because none of the positive numbers 2^k-51668657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51668677) 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, 1359683 + ... + 1359720.

It is an arithmetic number, because the mean of its divisors is an integer number (13597020).

Almost surely, 2^51668657 is an apocalyptic number.

It is an amenable number.

51668657 is a deficient number, since it is larger than the sum of its proper divisors (2719423).

51668657 is a wasteful number, since it uses less digits than its factorization.

51668657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2719422.

The product of its digits is 302400, while the sum is 44.

The square root of 51668657 is about 7188.0913321966. The cubic root of 51668657 is about 372.4566428524.

It can be divided in two parts, 51668 and 657, that added together give a palindrome (52325).

The spelling of 51668657 in words is "fifty-one million, six hundred sixty-eight thousand, six hundred fifty-seven".