665268075920 has 80 divisors (see below), whose sum is σ = 1828667957760. Its totient is φ = 220226668032.

The previous prime is 665268075917. The next prime is 665268075947. The reversal of 665268075920 is 29570862566.

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

It is a super-2 number, since 2×665268075920² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20466152 + ... + 20498631.

It is an arithmetic number, because the mean of its divisors is an integer number (22858349472).

Almost surely, 2^665268075920 is an apocalyptic number.

It is an amenable number.

665268075920 is an abundant number, since it is smaller than the sum of its proper divisors (1163399881840).

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

665268075920 is a wasteful number, since it uses less digits than its factorization.

665268075920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40964832 (or 40964826 counting only the distinct ones).

The product of its (nonzero) digits is 10886400, while the sum is 56.

The spelling of 665268075920 in words is "six hundred sixty-five billion, two hundred sixty-eight million, seventy-five thousand, nine hundred twenty".