198739381 has 2 divisors, whose sum is σ = 198739382. Its totient is φ = 198739380.

The previous prime is 198739327. The next prime is 198739397. The reversal of 198739381 is 183937891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153983281 + 44756100 = 12409^2 + 6690^2 .

It is an emirp because it is prime and its reverse (183937891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198739381 - 2¹⁹ = 198215093 is a prime.

It is a super-2 number, since 2×198739381² = 78994683120526322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198739301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99369690 + 99369691.

It is an arithmetic number, because the mean of its divisors is an integer number (99369691).

Almost surely, 2^198739381 is an apocalyptic number.

It is an amenable number.

198739381 is a deficient number, since it is larger than the sum of its proper divisors (1).

198739381 is an equidigital number, since it uses as much as digits as its factorization.

198739381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 49.

The square root of 198739381 is about 14097.4955577223. The cubic root of 198739381 is about 583.5722662741.

The spelling of 198739381 in words is "one hundred ninety-eight million, seven hundred thirty-nine thousand, three hundred eighty-one".