198880309 has 2 divisors, whose sum is σ = 198880310. Its totient is φ = 198880308.

The previous prime is 198880307. The next prime is 198880343. The reversal of 198880309 is 903088891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174821284 + 24059025 = 13222^2 + 4905^2 .

It is a cyclic number.

It is not a de Polignac number, because 198880309 - 2¹ = 198880307 is a prime.

Together with 198880307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198880303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99440154 + 99440155.

It is an arithmetic number, because the mean of its divisors is an integer number (99440155).

Almost surely, 2^198880309 is an apocalyptic number.

It is an amenable number.

198880309 is a deficient number, since it is larger than the sum of its proper divisors (1).

198880309 is an equidigital number, since it uses as much as digits as its factorization.

198880309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 46.

The square root of 198880309 is about 14102.4930065574. The cubic root of 198880309 is about 583.7101725782.

The spelling of 198880309 in words is "one hundred ninety-eight million, eight hundred eighty thousand, three hundred nine".