666738837666 has 48 divisors (see below), whose sum is σ = 1575995043168. Its totient is φ = 202033497600.

The previous prime is 666738837643. The next prime is 666738837679.

666738837666 is nontrivially palindromic in base 10.

666738837666 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 = 666738837594 and 666738837603.

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, 5836105 + ... + 5949251.

It is an arithmetic number, because the mean of its divisors is an integer number (32833230066).

Almost surely, 2^666738837666 is an apocalyptic number.

666738837666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

666738837666 is an abundant number, since it is smaller than the sum of its proper divisors (909256205502).

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

666738837666 is a wasteful number, since it uses less digits than its factorization.

666738837666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142927 (or 142924 counting only the distinct ones).

The product of its digits is 1316818944, while the sum is 72.

The spelling of 666738837666 in words is "six hundred sixty-six billion, seven hundred thirty-eight million, eight hundred thirty-seven thousand, six hundred sixty-six".