661150666506 has 32 divisors (see below), whose sum is σ = 1443899059200. Its totient is φ = 200155837680.

The previous prime is 661150666489. The next prime is 661150666511. The reversal of 661150666506 is 605666051166.

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, 4752136 + ... + 4889283.

It is an arithmetic number, because the mean of its divisors is an integer number (45121845600).

Almost surely, 2^661150666506 is an apocalyptic number.

661150666506 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

661150666506 is an abundant number, since it is smaller than the sum of its proper divisors (782748392694).

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

661150666506 is a wasteful number, since it uses less digits than its factorization.

661150666506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9642474.

The product of its (nonzero) digits is 1166400, while the sum is 48.

The spelling of 661150666506 in words is "six hundred sixty-one billion, one hundred fifty million, six hundred sixty-six thousand, five hundred six".