51364640 has 48 divisors (see below), whose sum is σ = 121927680. Its totient is φ = 20448000.

The previous prime is 51364639. The next prime is 51364739. The reversal of 51364640 is 4646315.

It is a happy 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, 39521 + ... + 40799.

It is an arithmetic number, because the mean of its divisors is an integer number (2540160).

Almost surely, 2^51364640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51364640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60963840).

51364640 is an abundant number, since it is smaller than the sum of its proper divisors (70563040).

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

51364640 is a wasteful number, since it uses less digits than its factorization.

51364640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1545 (or 1537 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 51364640 is about 7166.9128639882. The cubic root of 51364640 is about 371.7246970684.

The spelling of 51364640 in words is "fifty-one million, three hundred sixty-four thousand, six hundred forty".