198660251 has 4 divisors (see below), whose sum is σ = 201053832. Its totient is φ = 196266672.

The previous prime is 198660191. The next prime is 198660277. The reversal of 198660251 is 152066891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198660251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198662251) 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, 1196666 + ... + 1196831.

It is an arithmetic number, because the mean of its divisors is an integer number (50263458).

Almost surely, 2^198660251 is an apocalyptic number.

198660251 is a deficient number, since it is larger than the sum of its proper divisors (2393581).

198660251 is an equidigital number, since it uses as much as digits as its factorization.

198660251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2393580.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 198660251 is about 14094.6887514411. The cubic root of 198660251 is about 583.4948043516.

The spelling of 198660251 in words is "one hundred ninety-eight million, six hundred sixty thousand, two hundred fifty-one".