198959749 has 4 divisors (see below), whose sum is σ = 205820460. Its totient is φ = 192099040.

The previous prime is 198959723. The next prime is 198959777. The reversal of 198959749 is 947959891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 947959891 = 8863 ⋅106957.

It can be written as a sum of positive squares in 2 ways, for example, as 95062500 + 103897249 = 9750^2 + 10193^2 .

It is a cyclic number.

It is not a de Polignac number, because 198959749 - 2¹⁷ = 198828677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198950749) 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, 3430312 + ... + 3430369.

It is an arithmetic number, because the mean of its divisors is an integer number (51455115).

Almost surely, 2^198959749 is an apocalyptic number.

It is an amenable number.

198959749 is a deficient number, since it is larger than the sum of its proper divisors (6860711).

198959749 is an equidigital number, since it uses as much as digits as its factorization.

198959749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6860710.

The product of its digits is 7348320, while the sum is 61.

The square root of 198959749 is about 14105.3092486482. The cubic root of 198959749 is about 583.7878805620.

The spelling of 198959749 in words is "one hundred ninety-eight million, nine hundred fifty-nine thousand, seven hundred forty-nine".