661115606166 has 48 divisors (see below), whose sum is σ = 1443640919760. Its totient is φ = 218651166720.

The previous prime is 661115606149. The next prime is 661115606197. The reversal of 661115606166 is 661606511166.

661115606166 is a `hidden beast` number, since 6 + 6 + 11 + 15 + 6 + 0 + 616 + 6 = 666.

It is a super-3 number, since 3×661115606166³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1065586 + ... + 1567706.

It is an arithmetic number, because the mean of its divisors is an integer number (30075852495).

Almost surely, 2^661115606166 is an apocalyptic number.

661115606166 is an abundant number, since it is smaller than the sum of its proper divisors (782525313594).

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

661115606166 is a wasteful number, since it uses less digits than its factorization.

661115606166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502701 (or 502698 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 661115606166 in words is "six hundred sixty-one billion, one hundred fifteen million, six hundred six thousand, one hundred sixty-six".