666837738666 has 48 divisors (see below), whose sum is σ = 1576246808448. Its totient is φ = 202061160000.

The previous prime is 666837738643. The next prime is 666837738683.

666837738666 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×666837738666² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 666837738594 and 666837738603.

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, 4078015 + ... + 4238381.

It is an arithmetic number, because the mean of its divisors is an integer number (32838475176).

Almost surely, 2^666837738666 is an apocalyptic number.

666837738666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

666837738666 is an abundant number, since it is smaller than the sum of its proper divisors (909409069782).

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

666837738666 is a wasteful number, since it uses less digits than its factorization.

666837738666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181387 (or 181384 counting only the distinct ones).

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

The spelling of 666837738666 in words is "six hundred sixty-six billion, eight hundred thirty-seven million, seven hundred thirty-eight thousand, six hundred sixty-six".