51644540 has 24 divisors (see below), whose sum is σ = 110763072. Its totient is φ = 20217920.

The previous prime is 51644533. The next prime is 51644561. The reversal of 51644540 is 4544615.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26531 + ... + 28410.

It is an arithmetic number, because the mean of its divisors is an integer number (4615128).

Almost surely, 2^51644540 is an apocalyptic number.

It is an amenable number.

51644540 is an abundant number, since it is smaller than the sum of its proper divisors (59118532).

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

51644540 is a wasteful number, since it uses less digits than its factorization.

51644540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54997 (or 54995 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 51644540 is about 7186.4135700640. The cubic root of 51644540 is about 372.3986842155.

The spelling of 51644540 in words is "fifty-one million, six hundred forty-four thousand, five hundred forty".