198888861 has 4 divisors (see below), whose sum is σ = 265185152. Its totient is φ = 132592572.

The previous prime is 198888857. The next prime is 198888883. The reversal of 198888861 is 168888891.

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.

It is not a de Polignac number, because 198888861 - 2² = 198888857 is a prime.

198888861 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198888841) 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, 33148141 + ... + 33148146.

It is an arithmetic number, because the mean of its divisors is an integer number (66296288).

Almost surely, 2^198888861 is an apocalyptic number.

It is an amenable number.

198888861 is a deficient number, since it is larger than the sum of its proper divisors (66296291).

198888861 is an equidigital number, since it uses as much as digits as its factorization.

198888861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66296290.

The product of its digits is 1769472, while the sum is 57.

The square root of 198888861 is about 14102.7962120992. The cubic root of 198888861 is about 583.7185391143.

The spelling of 198888861 in words is "one hundred ninety-eight million, eight hundred eighty-eight thousand, eight hundred sixty-one".