51809316 has 72 divisors (see below), whose sum is σ = 133428960. Its totient is φ = 15634944.

The previous prime is 51809299. The next prime is 51809357. The reversal of 51809316 is 61390815.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 119436 + ... + 119868.

It is an arithmetic number, because the mean of its divisors is an integer number (1853180).

Almost surely, 2^51809316 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 51809316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66714480).

51809316 is an abundant number, since it is smaller than the sum of its proper divisors (81619644).

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

51809316 is a wasteful number, since it uses less digits than its factorization.

51809316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 51809316 is about 7197.8688512642. The cubic root of 51809316 is about 372.7943195884.

It can be divided in two parts, 51809 and 316, that added together give a palindrome (52125).

The spelling of 51809316 in words is "fifty-one million, eight hundred nine thousand, three hundred sixteen".