198578749 has 2 divisors, whose sum is σ = 198578750. Its totient is φ = 198578748.

The previous prime is 198578701. The next prime is 198578767. The reversal of 198578749 is 947875891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 174715524 + 23863225 = 13218^2 + 4885^2 .

It is a cyclic number.

It is not a de Polignac number, because 198578749 - 2¹⁵ = 198545981 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 198578693 and 198578702.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198578789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99289374 + 99289375.

It is an arithmetic number, because the mean of its divisors is an integer number (99289375).

Almost surely, 2^198578749 is an apocalyptic number.

It is an amenable number.

198578749 is a deficient number, since it is larger than the sum of its proper divisors (1).

198578749 is an equidigital number, since it uses as much as digits as its factorization.

198578749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5080320, while the sum is 58.

The square root of 198578749 is about 14091.7972239172. The cubic root of 198578749 is about 583.4149989247.

The spelling of 198578749 in words is "one hundred ninety-eight million, five hundred seventy-eight thousand, seven hundred forty-nine".