198520381 has 2 divisors, whose sum is σ = 198520382. Its totient is φ = 198520380.

The previous prime is 198520369. The next prime is 198520391. The reversal of 198520381 is 183025891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 197655481 + 864900 = 14059^2 + 930^2 .

It is a cyclic number.

It is not a de Polignac number, because 198520381 - 2⁷ = 198520253 is a prime.

It is a super-2 number, since 2×198520381² = 78820683344770322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 198520381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198520391) 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 as a sum of consecutive naturals, namely, 99260190 + 99260191.

It is an arithmetic number, because the mean of its divisors is an integer number (99260191).

Almost surely, 2^198520381 is an apocalyptic number.

It is an amenable number.

198520381 is a deficient number, since it is larger than the sum of its proper divisors (1).

198520381 is an equidigital number, since it uses as much as digits as its factorization.

198520381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 198520381 is about 14089.7260796653. The cubic root of 198520381 is about 583.3578325130.

It can be divided in two parts, 1985 and 20381, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 198520381 in words is "one hundred ninety-eight million, five hundred twenty thousand, three hundred eighty-one".