198157791 has 16 divisors (see below), whose sum is σ = 284842880. Its totient is φ = 121811040.

The previous prime is 198157789. The next prime is 198157801. The reversal of 198157791 is 197751891.

It is not a de Polignac number, because 198157791 - 2¹ = 198157789 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 198157791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198157721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43500 + ... + 47838.

It is an arithmetic number, because the mean of its divisors is an integer number (17802680).

Almost surely, 2^198157791 is an apocalyptic number.

198157791 is a deficient number, since it is larger than the sum of its proper divisors (86685089).

198157791 is a wasteful number, since it uses less digits than its factorization.

198157791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5526.

The product of its digits is 158760, while the sum is 48.

The square root of 198157791 is about 14076.8530218938. The cubic root of 198157791 is about 583.0024556933.

The spelling of 198157791 in words is "one hundred ninety-eight million, one hundred fifty-seven thousand, seven hundred ninety-one".