198861877 has 2 divisors, whose sum is σ = 198861878. Its totient is φ = 198861876.

The previous prime is 198861863. The next prime is 198861899. The reversal of 198861877 is 778168891.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189090001 + 9771876 = 13751^2 + 3126^2 .

It is an emirp because it is prime and its reverse (778168891) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198861877 is a prime.

It is a super-2 number, since 2×198861877² = 79092092247926258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198861827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99430938 + 99430939.

It is an arithmetic number, because the mean of its divisors is an integer number (99430939).

Almost surely, 2^198861877 is an apocalyptic number.

It is an amenable number.

198861877 is a deficient number, since it is larger than the sum of its proper divisors (1).

198861877 is an equidigital number, since it uses as much as digits as its factorization.

198861877 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1354752, while the sum is 55.

The square root of 198861877 is about 14101.8394899389. The cubic root of 198861877 is about 583.6921394902.

The spelling of 198861877 in words is "one hundred ninety-eight million, eight hundred sixty-one thousand, eight hundred seventy-seven".