198878638 has 16 divisors (see below), whose sum is σ = 341157600. Its totient is φ = 85178016.

The previous prime is 198878527. The next prime is 198878639. The reversal of 198878638 is 836878891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198878639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23388 + ... + 30736.

It is an arithmetic number, because the mean of its divisors is an integer number (21322350).

Almost surely, 2^198878638 is an apocalyptic number.

198878638 is a deficient number, since it is larger than the sum of its proper divisors (142278962).

198878638 is a wasteful number, since it uses less digits than its factorization.

198878638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9291.

The product of its digits is 4644864, while the sum is 58.

The square root of 198878638 is about 14102.4337615888. The cubic root of 198878638 is about 583.7085377885.

The spelling of 198878638 in words is "one hundred ninety-eight million, eight hundred seventy-eight thousand, six hundred thirty-eight".