198647621666 has 48 divisors (see below), whose sum is σ = 324104815944. Its totient is φ = 91272609792.

The previous prime is 198647621609. The next prime is 198647621701. The reversal of 198647621666 is 666126746891.

It can be written as a sum of positive squares in 12 ways, for example, as 92717641 + 198554904025 = 9629^2 + 445595^2 .

It is a junction number, because it is equal to n+sod(n) for n = 198647621599 and 198647621608.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 138622886 + ... + 138624318.

Almost surely, 2^198647621666 is an apocalyptic number.

198647621666 is a deficient number, since it is larger than the sum of its proper divisors (125457194278).

198647621666 is a wasteful number, since it uses less digits than its factorization.

198647621666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3015 (or 3002 counting only the distinct ones).

The product of its digits is 31352832, while the sum is 62.

The spelling of 198647621666 in words is "one hundred ninety-eight billion, six hundred forty-seven million, six hundred twenty-one thousand, six hundred sixty-six".