661435868534166 has 72 divisors (see below), whose sum is σ = 1617811757863392. Its totient is φ = 195017946472800.

The previous prime is 661435868534123. The next prime is 661435868534213.

661435868534166 is a `hidden beast` number, since 6 + 6 + 1 + 4 + 3 + 5 + 86 + 8 + 534 + 1 + 6 + 6 = 666.

661435868534166 is nontrivially palindromic in base 10.

661435868534166 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 661435868534094 and 661435868534103.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4103832430 + ... + 4103993601.

Almost surely, 2^{661435868534166} is an apocalyptic number.

661435868534166 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

661435868534166 is an abundant number, since it is smaller than the sum of its proper divisors (956375889329226).

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

661435868534166 is a wasteful number, since it uses less digits than its factorization.

661435868534166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8207826098 (or 8207826084 counting only the distinct ones).

The product of its digits is 1791590400, while the sum is 72.

The spelling of 661435868534166 in words is "six hundred sixty-one trillion, four hundred thirty-five billion, eight hundred sixty-eight million, five hundred thirty-four thousand, one hundred sixty-six".