666666021552 has 40 divisors (see below), whose sum is σ = 1722252529200. Its totient is φ = 222217881600.

The previous prime is 666666021499. The next prime is 666666021557. The reversal of 666666021552 is 255120666666.

It is a junction number, because it is equal to n+sod(n) for n = 666666021495 and 666666021504.

It is not an unprimeable number, because it can be changed into a prime (666666021557) 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, 3588552 + ... + 3769752.

It is an arithmetic number, because the mean of its divisors is an integer number (43056313230).

Almost surely, 2^666666021552 is an apocalyptic number.

It is an amenable number.

666666021552 is an abundant number, since it is smaller than the sum of its proper divisors (1055586507648).

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

666666021552 is a wasteful number, since it uses less digits than its factorization.

666666021552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257861 (or 257855 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 51.

The spelling of 666666021552 in words is "six hundred sixty-six billion, six hundred sixty-six million, twenty-one thousand, five hundred fifty-two".