666666021200 has 60 divisors (see below), whose sum is σ = 1602006804288. Its totient is φ = 266609520000.

The previous prime is 666666021193. The next prime is 666666021277. The reversal of 666666021200 is 2120666666.

It is a super-4 number, since 4×666666021200⁴ (a number of 48 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1724999 + ... + 2075801.

Almost surely, 2^666666021200 is an apocalyptic number.

It is an amenable number.

666666021200 is an abundant number, since it is smaller than the sum of its proper divisors (935340783088).

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

666666021200 is a wasteful number, since it uses less digits than its factorization.

666666021200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355572 (or 355561 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 41.

Adding to 666666021200 its reverse (2120666666), we get a palindrome (668786687866).

The spelling of 666666021200 in words is "six hundred sixty-six billion, six hundred sixty-six million, twenty-one thousand, two hundred".