198138427 has 4 divisors (see below), whose sum is σ = 199990296. Its totient is φ = 196286560.

The previous prime is 198138419. The next prime is 198138443. The reversal of 198138427 is 724831891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 198138427 - 2³ = 198138419 is a prime.

It is a super-3 number, since 3×198138427³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198138407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 925774 + ... + 925987.

It is an arithmetic number, because the mean of its divisors is an integer number (49997574).

Almost surely, 2^198138427 is an apocalyptic number.

198138427 is a deficient number, since it is larger than the sum of its proper divisors (1851869).

198138427 is a wasteful number, since it uses less digits than its factorization.

198138427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1851868.

The product of its digits is 96768, while the sum is 43.

The square root of 198138427 is about 14076.1652093175. The cubic root of 198138427 is about 582.9834647211.

The spelling of 198138427 in words is "one hundred ninety-eight million, one hundred thirty-eight thousand, four hundred twenty-seven".