661656061200 has 120 divisors (see below), whose sum is σ = 2151139579168. Its totient is φ = 173808138240.

The previous prime is 661656061153. The next prime is 661656061207. The reversal of 661656061200 is 2160656166.

It is a tau number, because it is divible by the number of its divisors (120).

It is not an unprimeable number, because it can be changed into a prime (661656061207) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4034377 + ... + 4195176.

Almost surely, 2^661656061200 is an apocalyptic number.

661656061200 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

661656061200 is an abundant number, since it is smaller than the sum of its proper divisors (1489483517968).

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

661656061200 is a wasteful number, since it uses less digits than its factorization.

661656061200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8229641 (or 8229630 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 39.

The spelling of 661656061200 in words is "six hundred sixty-one billion, six hundred fifty-six million, sixty-one thousand, two hundred".