51319920 has 40 divisors (see below), whose sum is σ = 159092496. Its totient is φ = 13685248.

The previous prime is 51319913. The next prime is 51319943. The reversal of 51319920 is 2991315.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

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 7 ways as a sum of consecutive naturals, for example, 106677 + ... + 107156.

Almost surely, 2^51319920 is an apocalyptic number.

It is an amenable number.

51319920 is an abundant number, since it is smaller than the sum of its proper divisors (107772576).

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

51319920 is a wasteful number, since it uses less digits than its factorization.

51319920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213849 (or 213843 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 30.

The square root of 51319920 is about 7163.7922917963. The cubic root of 51319920 is about 371.6167865477.

It can be divided in two parts, 5131 and 9920, that added together give a palindrome (15051).

The spelling of 51319920 in words is "fifty-one million, three hundred nineteen thousand, nine hundred twenty".