51315216 has 40 divisors (see below), whose sum is σ = 132908160. Its totient is φ = 17060736.

The previous prime is 51315203. The next prime is 51315217. The reversal of 51315216 is 61251315.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51315217) 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, 21070 + ... + 23378.

It is an arithmetic number, because the mean of its divisors is an integer number (3322704).

Almost surely, 2^51315216 is an apocalyptic number.

It is an amenable number.

51315216 is an abundant number, since it is smaller than the sum of its proper divisors (81592944).

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

51315216 is a wasteful number, since it uses less digits than its factorization.

51315216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2783 (or 2777 counting only the distinct ones).

The product of its digits is 900, while the sum is 24.

The square root of 51315216 is about 7163.4639665458. The cubic root of 51315216 is about 371.6054320302.

The spelling of 51315216 in words is "fifty-one million, three hundred fifteen thousand, two hundred sixteen".