661949166 has 16 divisors (see below), whose sum is σ = 1359679824. Its totient is φ = 214686144.

The previous prime is 661949069. The next prime is 661949201.

661949166 is nontrivially palindromic in base 10.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1490655 + ... + 1491098.

It is an arithmetic number, because the mean of its divisors is an integer number (84979989).

Almost surely, 2^661949166 is an apocalyptic number.

661949166 is an abundant number, since it is smaller than the sum of its proper divisors (697730658).

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

661949166 is a wasteful number, since it uses less digits than its factorization.

661949166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2981795.

The product of its digits is 419904, while the sum is 48.

The square root of 661949166 is about 25728.3727818142. The cubic root of 661949166 is about 871.5150269837.

The spelling of 661949166 in words is "six hundred sixty-one million, nine hundred forty-nine thousand, one hundred sixty-six".