51515520 has 128 divisors (see below), whose sum is σ = 187712640. Its totient is φ = 11771904.

The previous prime is 51515509. The next prime is 51515533. The reversal of 51515520 is 2551515.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11524 + ... + 15356.

It is an arithmetic number, because the mean of its divisors is an integer number (1466505).

Almost surely, 2^51515520 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 51515520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93856320).

51515520 is an abundant number, since it is smaller than the sum of its proper divisors (136197120).

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

51515520 is a wasteful number, since it uses less digits than its factorization.

51515520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3862 (or 3850 counting only the distinct ones).

The product of its (nonzero) digits is 1250, while the sum is 24.

The square root of 51515520 is about 7177.4312953870. The cubic root of 51515520 is about 372.0883129442.

The spelling of 51515520 in words is "fifty-one million, five hundred fifteen thousand, five hundred twenty".