51991596 has 36 divisors (see below), whose sum is σ = 133280784. Its totient is φ = 17085600.

The previous prime is 51991591. The next prime is 51991603. The reversal of 51991596 is 69519915.

It is a happy number.

51991596 is a `hidden beast` number, since 51 + 9 + 9 + 1 + 596 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (51991591) 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 11 ways as a sum of consecutive naturals, for example, 7615 + ... + 12726.

It is an arithmetic number, because the mean of its divisors is an integer number (3702244).

Almost surely, 2^51991596 is an apocalyptic number.

It is an amenable number.

51991596 is an abundant number, since it is smaller than the sum of its proper divisors (81289188).

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

51991596 is a wasteful number, since it uses less digits than its factorization.

51991596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20422 (or 20417 counting only the distinct ones).

The product of its digits is 109350, while the sum is 45.

The square root of 51991596 is about 7210.5198148261. The cubic root of 51991596 is about 373.2310068908.

The spelling of 51991596 in words is "fifty-one million, nine hundred ninety-one thousand, five hundred ninety-six".