51123018816 has 63 divisors (see below), whose sum is σ = 146550458613. Its totient is φ = 17039197440.

The previous prime is 51123018811. The next prime is 51123018823. The reversal of 51123018816 is 61881032115.

The square root of 51123018816 is 226104.

It is a perfect power (a square), and thus also a powerful number.

51123018816 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 16616241216 + 34506777600 = 128904^2 + 185760^2 .

It is a super-2 number, since 2×51123018816² (a number of 22 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (51123018811) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5421786 + ... + 5431206.

Almost surely, 2^51123018816 is an apocalyptic number.

51123018816 is the 226104-th square number.

It is an amenable number.

51123018816 is an abundant number, since it is smaller than the sum of its proper divisors (95427439797).

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

51123018816 is an frugal number, since it uses more digits than its factorization.

51123018816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18860 (or 9426 counting only the distinct ones).

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

Multiplying 51123018816 by its sum of digits (36), we get a square (1840428677376 = 1356624²).

51123018816 divided by its sum of digits (36) gives a square (1420083856 = 37684²).

The spelling of 51123018816 in words is "fifty-one billion, one hundred twenty-three million, eighteen thousand, eight hundred sixteen".