198851309 has 4 divisors (see below), whose sum is σ = 198891840. Its totient is φ = 198810780.

The previous prime is 198851297. The next prime is 198851339. The reversal of 198851309 is 903158891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 198851309 - 2¹⁶ = 198785773 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 198851309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198851339) 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, 11699 + ... + 23120.

It is an arithmetic number, because the mean of its divisors is an integer number (49722960).

Almost surely, 2^198851309 is an apocalyptic number.

It is an amenable number.

198851309 is a deficient number, since it is larger than the sum of its proper divisors (40531).

198851309 is an equidigital number, since it uses as much as digits as its factorization.

198851309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40530.

The product of its (nonzero) digits is 77760, while the sum is 44.

The square root of 198851309 is about 14101.4647820714. The cubic root of 198851309 is about 583.6817997042.

The spelling of 198851309 in words is "one hundred ninety-eight million, eight hundred fifty-one thousand, three hundred nine".