51591906 has 24 divisors (see below), whose sum is σ = 118358604. Its totient is φ = 16185600.

The previous prime is 51591877. The next prime is 51591907. The reversal of 51591906 is 60919515.

51591906 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 50765625 + 826281 = 7125^2 + 909^2 .

It is not an unprimeable number, because it can be changed into a prime (51591907) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 83995 + ... + 84606.

Almost surely, 2^51591906 is an apocalyptic number.

51591906 is an abundant number, since it is smaller than the sum of its proper divisors (66766698).

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

51591906 is a wasteful number, since it uses less digits than its factorization.

51591906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168626 (or 168623 counting only the distinct ones).

The product of its (nonzero) digits is 12150, while the sum is 36.

The square root of 51591906 is about 7182.7505873447. The cubic root of 51591906 is about 372.2721300505.

The spelling of 51591906 in words is "fifty-one million, five hundred ninety-one thousand, nine hundred six".