198878421 has 32 divisors (see below), whose sum is σ = 309899520. Its totient is φ = 111108096.

The previous prime is 198878417. The next prime is 198878429. The reversal of 198878421 is 124878891.

It is not a de Polignac number, because 198878421 - 2² = 198878417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198878429) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 180745 + ... + 181841.

It is an arithmetic number, because the mean of its divisors is an integer number (9684360).

Almost surely, 2^198878421 is an apocalyptic number.

It is an amenable number.

198878421 is a deficient number, since it is larger than the sum of its proper divisors (111021099).

198878421 is a wasteful number, since it uses less digits than its factorization.

198878421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1293.

The product of its digits is 258048, while the sum is 48.

The square root of 198878421 is about 14102.4260678792. The cubic root of 198878421 is about 583.7083254902.

The spelling of 198878421 in words is "one hundred ninety-eight million, eight hundred seventy-eight thousand, four hundred twenty-one".