661646166 has 32 divisors (see below), whose sum is σ = 1357240320. Its totient is φ = 214931136.

The previous prime is 661646159. The next prime is 661646179.

661646166 is nontrivially palindromic in base 10.

It is a congruent number.

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, 62490 + ... + 72306.

It is an arithmetic number, because the mean of its divisors is an integer number (42413760).

Almost surely, 2^661646166 is an apocalyptic number.

661646166 is an abundant number, since it is smaller than the sum of its proper divisors (695594154).

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

661646166 is a wasteful number, since it uses less digits than its factorization.

661646166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10108.

The product of its digits is 186624, while the sum is 42.

The square root of 661646166 is about 25722.4836670178. The cubic root of 661646166 is about 871.3820311946.

The spelling of 661646166 in words is "six hundred sixty-one million, six hundred forty-six thousand, one hundred sixty-six".