661510165632 has 64 divisors (see below), whose sum is σ = 1761773008800. Its totient is φ = 219921537024.

The previous prime is 661510165601. The next prime is 661510165697. The reversal of 661510165632 is 236561015166.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2127133 + ... + 2418204.

Almost surely, 2^661510165632 is an apocalyptic number.

It is an amenable number.

661510165632 is an abundant number, since it is smaller than the sum of its proper divisors (1100262843168).

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

661510165632 is a wasteful number, since it uses less digits than its factorization.

661510165632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4545733 (or 4545721 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 42.

The spelling of 661510165632 in words is "six hundred sixty-one billion, five hundred ten million, one hundred sixty-five thousand, six hundred thirty-two".