198916861 has 12 divisors (see below), whose sum is σ = 235464796. Its totient is φ = 166921920.

The previous prime is 198916859. The next prime is 198916867. The reversal of 198916861 is 168619891.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 40005625 + 158911236 = 6325^2 + 12606^2 .

It is not a de Polignac number, because 198916861 - 2¹ = 198916859 is a prime.

198916861 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 (198916867) 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, 61656 + ... + 64801.

Almost surely, 2^198916861 is an apocalyptic number.

198916861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

198916861 is a deficient number, since it is larger than the sum of its proper divisors (36547935).

198916861 is a wasteful number, since it uses less digits than its factorization.

198916861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126492 (or 126481 counting only the distinct ones).

The product of its digits is 186624, while the sum is 49.

The square root of 198916861 is about 14103.7888880967. The cubic root of 198916861 is about 583.7459302111.

The spelling of 198916861 in words is "one hundred ninety-eight million, nine hundred sixteen thousand, eight hundred sixty-one".