51185320 has 64 divisors (see below), whose sum is σ = 118972800. Its totient is φ = 19810560.

The previous prime is 51185311. The next prime is 51185339. The reversal of 51185320 is 2358115.

It is a happy 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, 190146 + ... + 190414.

It is an arithmetic number, because the mean of its divisors is an integer number (1858950).

Almost surely, 2^51185320 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 51185320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59486400).

51185320 is an abundant number, since it is smaller than the sum of its proper divisors (67787480).

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

51185320 is a wasteful number, since it uses less digits than its factorization.

51185320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 414 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 51185320 is about 7154.3916582754. The cubic root of 51185320 is about 371.2916144821.

The spelling of 51185320 in words is "fifty-one million, one hundred eighty-five thousand, three hundred twenty".