198978981 has 8 divisors (see below), whose sum is σ = 266045760. Its totient is φ = 132282432.

The previous prime is 198978973. The next prime is 198979009. The reversal of 198978981 is 189879891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 198978981 - 2³ = 198978973 is a prime.

It is a super-2 number, since 2×198978981² = 79185269759596722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198978961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91300 + ... + 93453.

It is an arithmetic number, because the mean of its divisors is an integer number (33255720).

Almost surely, 2^198978981 is an apocalyptic number.

It is an amenable number.

198978981 is a deficient number, since it is larger than the sum of its proper divisors (67066779).

198978981 is a wasteful number, since it uses less digits than its factorization.

198978981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185115.

The product of its digits is 2612736, while the sum is 60.

The square root of 198978981 is about 14105.9909612902. The cubic root of 198978981 is about 583.8066901401.

The spelling of 198978981 in words is "one hundred ninety-eight million, nine hundred seventy-eight thousand, nine hundred eighty-one".