198231561 has 12 divisors (see below), whose sum is σ = 312365040. Its totient is φ = 120140280.

The previous prime is 198231557. The next prime is 198231587. The reversal of 198231561 is 165132891.

198231561 is a `hidden beast` number, since 1 + 98 + 2 + 3 + 1 + 561 = 666.

It is not a de Polignac number, because 198231561 - 2² = 198231557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (198231511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1001071 + ... + 1001268.

It is an arithmetic number, because the mean of its divisors is an integer number (26030420).

Almost surely, 2^198231561 is an apocalyptic number.

198231561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

198231561 is a deficient number, since it is larger than the sum of its proper divisors (114133479).

198231561 is a wasteful number, since it uses less digits than its factorization.

198231561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2002356 (or 2002353 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 198231561 is about 14079.4730370138. The cubic root of 198231561 is about 583.0747932566.

The spelling of 198231561 in words is "one hundred ninety-eight million, two hundred thirty-one thousand, five hundred sixty-one".