198717381 has 16 divisors (see below), whose sum is σ = 298033920. Its totient is φ = 132476796.

The previous prime is 198717317. The next prime is 198717433. The reversal of 198717381 is 183717891.

It is a happy number.

It is not a de Polignac number, because 198717381 - 2⁶ = 198717317 is a prime.

It is a super-2 number, since 2×198717381² = 78977195022998322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198715381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43245 + ... + 47618.

It is an arithmetic number, because the mean of its divisors is an integer number (18627120).

Almost surely, 2^198717381 is an apocalyptic number.

It is an amenable number.

198717381 is a deficient number, since it is larger than the sum of its proper divisors (99316539).

198717381 is an frugal number, since it uses more digits than its factorization.

198717381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90884 (or 90866 counting only the distinct ones).

The product of its digits is 84672, while the sum is 45.

The square root of 198717381 is about 14096.7152556899. The cubic root of 198717381 is about 583.5507321028.

It can be divided in two parts, 19 and 8717381, that added together give a triangular number (8717400 = T₄₁₇₅).

The spelling of 198717381 in words is "one hundred ninety-eight million, seven hundred seventeen thousand, three hundred eighty-one".