666826479936 has 42 divisors (see below), whose sum is σ = 1911337707162. Its totient is φ = 222275493120.

The previous prime is 666826479923. The next prime is 666826479961. The reversal of 666826479936 is 639974628666.

It can be written as a sum of positive squares in only one way, i.e., 655322630400 + 11503849536 = 809520^2 + 107256^2 .

It is a super-2 number, since 2×666826479936² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

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 5 ways as a sum of consecutive naturals, for example, 578841855 + ... + 578843006.

Almost surely, 2^666826479936 is an apocalyptic number.

It is an amenable number.

666826479936 is an abundant number, since it is smaller than the sum of its proper divisors (1244511227226).

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

666826479936 is a wasteful number, since it uses less digits than its factorization.

666826479936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157684879 (or 1157684866 counting only the distinct ones).

The product of its digits is 846526464, while the sum is 72.

The spelling of 666826479936 in words is "six hundred sixty-six billion, eight hundred twenty-six million, four hundred seventy-nine thousand, nine hundred thirty-six".