665378022528 has 120 divisors (see below), whose sum is σ = 1980401423715. Its totient is φ = 221764988160.

The previous prime is 665378022479. The next prime is 665378022539. The reversal of 665378022528 is 825220873566.

It is a happy number.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

665378022528 is a `hidden beast` number, since 6 + 6 + 5 + 37 + 80 + 2 + 2 + 528 = 666.

665378022528 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., 332689011264 + 332689011264 = 576792^2 + 576792^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=576792.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 83054043 + ... + 83062053.

Almost surely, 2^665378022528 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 665378022528

665378022528 is an abundant number, since it is smaller than the sum of its proper divisors (1315023401187).

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

665378022528 is an frugal number, since it uses more digits than its factorization.

665378022528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16048 (or 8016 counting only the distinct ones).

The product of its (nonzero) digits is 9676800, while the sum is 54.

The spelling of 665378022528 in words is "six hundred sixty-five billion, three hundred seventy-eight million, twenty-two thousand, five hundred twenty-eight".