198521138 has 16 divisors (see below), whose sum is σ = 322009344. Its totient is φ = 91433280.

The previous prime is 198521137. The next prime is 198521149. The reversal of 198521138 is 831125891.

198521138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (198521137) 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, 60518 + ... + 63713.

It is an arithmetic number, because the mean of its divisors is an integer number (20125584).

Almost surely, 2^198521138 is an apocalyptic number.

198521138 is a deficient number, since it is larger than the sum of its proper divisors (123488206).

198521138 is a wasteful number, since it uses less digits than its factorization.

198521138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124297.

The product of its digits is 17280, while the sum is 38.

The square root of 198521138 is about 14089.7529431853. The cubic root of 198521138 is about 583.3585740008.

The spelling of 198521138 in words is "one hundred ninety-eight million, five hundred twenty-one thousand, one hundred thirty-eight".