51681756 has 24 divisors (see below), whose sum is σ = 137818240. Its totient is φ = 14766192.

The previous prime is 51681739. The next prime is 51681779. The reversal of 51681756 is 65718615.

51681756 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 7 ways as a sum of consecutive naturals, for example, 307546 + ... + 307713.

Almost surely, 2^51681756 is an apocalyptic number.

It is an amenable number.

51681756 is an abundant number, since it is smaller than the sum of its proper divisors (86136484).

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

51681756 is a wasteful number, since it uses less digits than its factorization.

51681756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615273 (or 615271 counting only the distinct ones).

The product of its digits is 50400, while the sum is 39.

The square root of 51681756 is about 7189.0024342742. The cubic root of 51681756 is about 372.4881151712.

The spelling of 51681756 in words is "fifty-one million, six hundred eighty-one thousand, seven hundred fifty-six".