666061275520 has 64 divisors (see below), whose sum is σ = 1593100761840. Its totient is φ = 266290984960.

The previous prime is 666061275403. The next prime is 666061275557. The reversal of 666061275520 is 25572160666.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1022130 + ... + 1541710.

Almost surely, 2^666061275520 is an apocalyptic number.

It is an amenable number.

666061275520 is an abundant number, since it is smaller than the sum of its proper divisors (927039486320).

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

666061275520 is a wasteful number, since it uses less digits than its factorization.

666061275520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521603 (or 521591 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 46.

The spelling of 666061275520 in words is "six hundred sixty-six billion, sixty-one million, two hundred seventy-five thousand, five hundred twenty".