51668311440 has 80 divisors (see below), whose sum is σ = 161757700416. Its totient is φ = 13641792000.

The previous prime is 51668311411. The next prime is 51668311441. The reversal of 51668311440 is 4411386615.

51668311440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×51668311440² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51668311441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1041526 + ... + 1090005.

Almost surely, 2^51668311440 is an apocalyptic number.

It is an amenable number.

51668311440 is an abundant number, since it is smaller than the sum of its proper divisors (110089388976).

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

51668311440 is a wasteful number, since it uses less digits than its factorization.

51668311440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2131648 (or 2131642 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The spelling of 51668311440 in words is "fifty-one billion, six hundred sixty-eight million, three hundred eleven thousand, four hundred forty".