198521649 has 6 divisors (see below), whose sum is σ = 286753506. Its totient is φ = 132347760.

The previous prime is 198521629. The next prime is 198521651. The reversal of 198521649 is 946125891.

It can be written as a sum of positive squares in only one way, i.e., 105206049 + 93315600 = 10257^2 + 9660^2 .

It is not a de Polignac number, because 198521649 - 2⁹ = 198521137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (198521629) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11028972 + ... + 11028989.

It is an arithmetic number, because the mean of its divisors is an integer number (47792251).

Almost surely, 2^198521649 is an apocalyptic number.

It is an amenable number.

198521649 is a deficient number, since it is larger than the sum of its proper divisors (88231857).

198521649 is a wasteful number, since it uses less digits than its factorization.

198521649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22057967 (or 22057964 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 198521649 is about 14089.7710769196. The cubic root of 198521649 is about 583.3590745285.

The spelling of 198521649 in words is "one hundred ninety-eight million, five hundred twenty-one thousand, six hundred forty-nine".