198409887 has 18 divisors (see below), whose sum is σ = 310335792. Its totient is φ = 122097456.

The previous prime is 198409879. The next prime is 198409901. The reversal of 198409887 is 788904891.

It is not a de Polignac number, because 198409887 - 2³ = 198409879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198409817) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 63703 + ... + 66744.

Almost surely, 2^198409887 is an apocalyptic number.

198409887 is a deficient number, since it is larger than the sum of its proper divisors (111925905).

198409887 is a wasteful number, since it uses less digits than its factorization.

198409887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130479 (or 130463 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 54.

The square root of 198409887 is about 14085.8044498708. The cubic root of 198409887 is about 583.2495824978.

The spelling of 198409887 in words is "one hundred ninety-eight million, four hundred nine thousand, eight hundred eighty-seven".