198358891 has 2 divisors, whose sum is σ = 198358892. Its totient is φ = 198358890.

The previous prime is 198358837. The next prime is 198358931. The reversal of 198358891 is 198853891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 198358891 - 2¹¹ = 198356843 is a prime.

It is not a weakly prime, because it can be changed into another prime (198358291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99179445 + 99179446.

It is an arithmetic number, because the mean of its divisors is an integer number (99179446).

Almost surely, 2^198358891 is an apocalyptic number.

198358891 is the 8908-th centered pentagonal number.

198358891 is a deficient number, since it is larger than the sum of its proper divisors (1).

198358891 is an equidigital number, since it uses as much as digits as its factorization.

198358891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 622080, while the sum is 52.

The square root of 198358891 is about 14083.9941422879. The cubic root of 198358891 is about 583.1996086032.

The spelling of 198358891 in words is "one hundred ninety-eight million, three hundred fifty-eight thousand, eight hundred ninety-one".