198640121776 has 20 divisors (see below), whose sum is σ = 384875648872. Its totient is φ = 99317373696.

The previous prime is 198640121773. The next prime is 198640121777. The reversal of 198640121776 is 677121046891.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (198640121773) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 529720 + ... + 823336.

Almost surely, 2^198640121776 is an apocalyptic number.

198640121776 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

198640121776 is a deficient number, since it is larger than the sum of its proper divisors (186235527096).

198640121776 is a wasteful number, since it uses less digits than its factorization.

198640121776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335908 (or 335902 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 52.

The spelling of 198640121776 in words is "one hundred ninety-eight billion, six hundred forty million, one hundred twenty-one thousand, seven hundred seventy-six".