51287520 has 96 divisors (see below), whose sum is σ = 164384640. Its totient is φ = 13437440.

The previous prime is 51287503. The next prime is 51287543. The reversal of 51287520 is 2578215.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 27415 + ... + 29225.

It is an arithmetic number, because the mean of its divisors is an integer number (1712340).

Almost surely, 2^51287520 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 51287520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82192320).

51287520 is an abundant number, since it is smaller than the sum of its proper divisors (113097120).

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

51287520 is a wasteful number, since it uses less digits than its factorization.

51287520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1888 (or 1880 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 51287520 is about 7161.5305626661. The cubic root of 51287520 is about 371.5385653384.

The spelling of 51287520 in words is "fifty-one million, two hundred eighty-seven thousand, five hundred twenty".