198722779 has 4 divisors (see below), whose sum is σ = 198857376. Its totient is φ = 198588184.

The previous prime is 198722701. The next prime is 198722789. The reversal of 198722779 is 977227891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 198722779 - 2⁹ = 198722267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198722789) 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, 65059 + ... + 68044.

It is an arithmetic number, because the mean of its divisors is an integer number (49714344).

Almost surely, 2^198722779 is an apocalyptic number.

198722779 is a deficient number, since it is larger than the sum of its proper divisors (134597).

198722779 is a wasteful number, since it uses less digits than its factorization.

198722779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134596.

The product of its digits is 889056, while the sum is 52.

The square root of 198722779 is about 14096.9067174327. The cubic root of 198722779 is about 583.5560159525.

The spelling of 198722779 in words is "one hundred ninety-eight million, seven hundred twenty-two thousand, seven hundred seventy-nine".