51315870 has 16 divisors (see below), whose sum is σ = 123158160. Its totient is φ = 13684224.

The previous prime is 51315841. The next prime is 51315871. The reversal of 51315870 is 7851315.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 1710529 = 51315870 / (5 + 1 + 3 + 1 + 5 + 8 + 7 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51315871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 855235 + ... + 855294.

It is an arithmetic number, because the mean of its divisors is an integer number (7697385).

Almost surely, 2^51315870 is an apocalyptic number.

51315870 is an abundant number, since it is smaller than the sum of its proper divisors (71842290).

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

51315870 is a wasteful number, since it uses less digits than its factorization.

51315870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1710539.

The product of its (nonzero) digits is 4200, while the sum is 30.

The square root of 51315870 is about 7163.5096147070. The cubic root of 51315870 is about 371.6070106973.

The spelling of 51315870 in words is "fifty-one million, three hundred fifteen thousand, eight hundred seventy".