51665656 has 16 divisors (see below), whose sum is σ = 110712240. Its totient is φ = 22142400.

The previous prime is 51665609. The next prime is 51665687. The reversal of 51665656 is 65656615.

51665656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

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, 461245 + ... + 461356.

It is an arithmetic number, because the mean of its divisors is an integer number (6919515).

Almost surely, 2^51665656 is an apocalyptic number.

51665656 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

51665656 is an abundant number, since it is smaller than the sum of its proper divisors (59046584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51665656 is a wasteful number, since it uses less digits than its factorization.

51665656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 922614 (or 922610 counting only the distinct ones).

The product of its digits is 162000, while the sum is 40.

The square root of 51665656 is about 7187.8825811222. The cubic root of 51665656 is about 372.4494317494.

It can be divided in two parts, 5 and 1665656, that added together give a palindrome (1665661).

The spelling of 51665656 in words is "fifty-one million, six hundred sixty-five thousand, six hundred fifty-six".