666998890000 has 75 divisors (see below), whose sum is σ = 1615068768027. Its totient is φ = 266766888000.

The previous prime is 666998889959. The next prime is 666998890007. The reversal of 666998890000 is 98899666.

The square root of 666998890000 is 816700.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 52292712976 + 614706177024 = 228676^2 + 784032^2 .

It is a super-2 number, since 2×666998890000² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666998890007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 81665917 + ... + 81674083.

Almost surely, 2^666998890000 is an apocalyptic number.

666998890000 is the 816700-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666998890000

666998890000 is an abundant number, since it is smaller than the sum of its proper divisors (948069878027).

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

666998890000 is an frugal number, since it uses more digits than its factorization.

666998890000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16362 (or 8174 counting only the distinct ones).

The product of its (nonzero) digits is 10077696, while the sum is 61.

The spelling of 666998890000 in words is "six hundred sixty-six billion, nine hundred ninety-eight million, eight hundred ninety thousand".