198861881 has 4 divisors (see below), whose sum is σ = 201379200. Its totient is φ = 196344564.

The previous prime is 198861877. The next prime is 198861899. The reversal of 198861881 is 188168891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 188168891 = 8231 ⋅22861.

It is a cyclic number.

It is not a de Polignac number, because 198861881 - 2² = 198861877 is a prime.

It is a super-2 number, since 2×198861881² = 79092095429716322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198861851) 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, 1258541 + ... + 1258698.

It is an arithmetic number, because the mean of its divisors is an integer number (50344800).

Almost surely, 2^198861881 is an apocalyptic number.

It is an amenable number.

198861881 is a deficient number, since it is larger than the sum of its proper divisors (2517319).

198861881 is an equidigital number, since it uses as much as digits as its factorization.

198861881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2517318.

The product of its digits is 221184, while the sum is 50.

The square root of 198861881 is about 14101.8396317644. The cubic root of 198861881 is about 583.6921434038.

The spelling of 198861881 in words is "one hundred ninety-eight million, eight hundred sixty-one thousand, eight hundred eighty-one".