6423203979666 has 12 divisors (see below), whose sum is σ = 13916941955982. Its totient is φ = 2141067993216.

The previous prime is 6423203979637. The next prime is 6423203979677. The reversal of 6423203979666 is 6669793023246.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 5691445205625 + 731758774041 = 2385675^2 + 855429^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 178422332751 + ... + 178422332786.

Almost surely, 2^{6423203979666} is an apocalyptic number.

6423203979666 is an abundant number, since it is smaller than the sum of its proper divisors (7493737976316).

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

6423203979666 is a wasteful number, since it uses less digits than its factorization.

6423203979666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356844665545 (or 356844665542 counting only the distinct ones).

The product of its (nonzero) digits is 105815808, while the sum is 63.

The spelling of 6423203979666 in words is "six trillion, four hundred twenty-three billion, two hundred three million, nine hundred seventy-nine thousand, six hundred sixty-six".