51689808 has 60 divisors (see below), whose sum is σ = 145168660. Its totient is φ = 17169408.

The previous prime is 51689773. The next prime is 51689821. The reversal of 51689808 is 80898615.

It can be written as a sum of positive squares in 2 ways, for example, as 16548624 + 35141184 = 4068^2 + 5928^2 .

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 61938 + ... + 62766.

Almost surely, 2^51689808 is an apocalyptic number.

It is an amenable number.

51689808 is an abundant number, since it is smaller than the sum of its proper divisors (93478852).

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

51689808 is a wasteful number, since it uses less digits than its factorization.

51689808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1276 (or 1267 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The square root of 51689808 is about 7189.5624345297. The cubic root of 51689808 is about 372.5074586738.

The spelling of 51689808 in words is "fifty-one million, six hundred eighty-nine thousand, eight hundred eight".