51665957 has 4 divisors (see below), whose sum is σ = 59046816. Its totient is φ = 44285100.

The previous prime is 51665953. The next prime is 51665989. The reversal of 51665957 is 75956615.

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 51665957 - 2² = 51665953 is a prime.

It is a super-2 number, since 2×51665957² = 5338742225451698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51665953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3690419 + ... + 3690432.

It is an arithmetic number, because the mean of its divisors is an integer number (14761704).

Almost surely, 2^51665957 is an apocalyptic number.

It is an amenable number.

51665957 is a deficient number, since it is larger than the sum of its proper divisors (7380859).

51665957 is an equidigital number, since it uses as much as digits as its factorization.

51665957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7380858.

The product of its digits is 283500, while the sum is 44.

The square root of 51665957 is about 7187.9035191076. The cubic root of 51665957 is about 372.4501550349.

The spelling of 51665957 in words is "fifty-one million, six hundred sixty-five thousand, nine hundred fifty-seven".