51654640 has 20 divisors (see below), whose sum is σ = 120097224. Its totient is φ = 20661824.

The previous prime is 51654601. The next prime is 51654643. The reversal of 51654640 is 4645615.

51654640 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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (51654643) 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, 322762 + ... + 322921.

Almost surely, 2^51654640 is an apocalyptic number.

It is an amenable number.

51654640 is an abundant number, since it is smaller than the sum of its proper divisors (68442584).

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

51654640 is a wasteful number, since it uses less digits than its factorization.

51654640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645696 (or 645690 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 51654640 is about 7187.1162506251. The cubic root of 51654640 is about 372.4229590084.

The spelling of 51654640 in words is "fifty-one million, six hundred fifty-four thousand, six hundred forty".