51186816 has 80 divisors (see below), whose sum is σ = 152361990. Its totient is φ = 17058816.

The previous prime is 51186787. The next prime is 51186823. The reversal of 51186816 is 61868115.

It can be written as a sum of positive squares in only one way, i.e., 44836416 + 6350400 = 6696^2 + 2520^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 7900 + ... + 12836.

Almost surely, 2^51186816 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 51186816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76180995).

51186816 is an abundant number, since it is smaller than the sum of its proper divisors (101175174).

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

51186816 is an equidigital number, since it uses as much as digits as its factorization.

51186816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4963 (or 4942 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 51186816 is about 7154.4962086788. The cubic root of 51186816 is about 371.2952317096.

The spelling of 51186816 in words is "fifty-one million, one hundred eighty-six thousand, eight hundred sixteen".