666021274644 has 24 divisors (see below), whose sum is σ = 1695326881248. Its totient is φ = 201824628640.

The previous prime is 666021274631. The next prime is 666021274649. The reversal of 666021274644 is 446472120666.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 666021274593 and 666021274602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666021274649) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 2522807727 + ... + 2522807990.

It is an arithmetic number, because the mean of its divisors is an integer number (70638620052).

Almost surely, 2^666021274644 is an apocalyptic number.

It is an amenable number.

666021274644 is an abundant number, since it is smaller than the sum of its proper divisors (1029305606604).

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

666021274644 is a wasteful number, since it uses less digits than its factorization.

666021274644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5045615735 (or 5045615733 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 48.

The spelling of 666021274644 in words is "six hundred sixty-six billion, twenty-one million, two hundred seventy-four thousand, six hundred forty-four".