666198089790 has 64 divisors (see below), whose sum is σ = 1621896480000. Its totient is φ = 175098288384.

The previous prime is 666198089789. The next prime is 666198089801. The reversal of 666198089790 is 97980891666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3090961 + ... + 3299459.

It is an arithmetic number, because the mean of its divisors is an integer number (25342132500).

Almost surely, 2^666198089790 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666198089790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (810948240000).

666198089790 is an abundant number, since it is smaller than the sum of its proper divisors (955698390210).

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

666198089790 is a wasteful number, since it uses less digits than its factorization.

666198089790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210041.

The product of its (nonzero) digits is 70543872, while the sum is 69.

The spelling of 666198089790 in words is "six hundred sixty-six billion, one hundred ninety-eight million, eighty-nine thousand, seven hundred ninety".