660621554816 has 32 divisors (see below), whose sum is σ = 1358536270080. Its totient is φ = 319655589120.

The previous prime is 660621554797. The next prime is 660621554833. The reversal of 660621554816 is 618455126066.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83239676 + ... + 83247611.

It is an arithmetic number, because the mean of its divisors is an integer number (42454258440).

Almost surely, 2^660621554816 is an apocalyptic number.

It is an amenable number.

660621554816 is an abundant number, since it is smaller than the sum of its proper divisors (697914715264).

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

660621554816 is a wasteful number, since it uses less digits than its factorization.

660621554816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166487332 (or 166487320 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 50.

The spelling of 660621554816 in words is "six hundred sixty billion, six hundred twenty-one million, five hundred fifty-four thousand, eight hundred sixteen".