666126621666 has 64 divisors (see below), whose sum is σ = 1614987538560. Its totient is φ = 201839662080.

The previous prime is 666126621653. The next prime is 666126621683.

666126621666 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8309970 + ... + 8389746.

It is an arithmetic number, because the mean of its divisors is an integer number (25234180290).

Almost surely, 2^666126621666 is an apocalyptic number.

666126621666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

666126621666 is an abundant number, since it is smaller than the sum of its proper divisors (948860916894).

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

666126621666 is a wasteful number, since it uses less digits than its factorization.

666126621666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93856 (or 93850 counting only the distinct ones).

The product of its digits is 6718464, while the sum is 54.

The spelling of 666126621666 in words is "six hundred sixty-six billion, one hundred twenty-six million, six hundred twenty-one thousand, six hundred sixty-six".