51329840 has 20 divisors (see below), whose sum is σ = 119342064. Its totient is φ = 20531904.

The previous prime is 51329833. The next prime is 51329843. The reversal of 51329840 is 4892315.

51329840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 51329797 and 51329806.

It is not an unprimeable number, because it can be changed into a prime (51329843) 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 3 ways as a sum of consecutive naturals, for example, 320732 + ... + 320891.

Almost surely, 2^51329840 is an apocalyptic number.

It is an amenable number.

51329840 is an abundant number, since it is smaller than the sum of its proper divisors (68012224).

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

51329840 is a wasteful number, since it uses less digits than its factorization.

51329840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641636 (or 641630 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 51329840 is about 7164.4846290574. The cubic root of 51329840 is about 371.6407291741.

The spelling of 51329840 in words is "fifty-one million, three hundred twenty-nine thousand, eight hundred forty".