198603891261 has 72 divisors (see below), whose sum is σ = 298373231520. Its totient is φ = 127251273600.

The previous prime is 198603891251. The next prime is 198603891281. The reversal of 198603891261 is 162198306891.

198603891261 is a `hidden beast` number, since 1 + 9 + 8 + 603 + 8 + 9 + 1 + 26 + 1 = 666.

It is not a de Polignac number, because 198603891261 - 2⁷ = 198603891133 is a prime.

It is a super-2 number, since 2×198603891261² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 198603891198 and 198603891207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198603891221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 510549655 + ... + 510550043.

It is an arithmetic number, because the mean of its divisors is an integer number (4144072660).

Almost surely, 2^198603891261 is an apocalyptic number.

It is an amenable number.

198603891261 is a deficient number, since it is larger than the sum of its proper divisors (99769340259).

198603891261 is a wasteful number, since it uses less digits than its factorization.

198603891261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747 (or 643 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 198603891261 in words is "one hundred ninety-eight billion, six hundred three million, eight hundred ninety-one thousand, two hundred sixty-one".