198157789 has 2 divisors, whose sum is σ = 198157790. Its totient is φ = 198157788.

The previous prime is 198157747. The next prime is 198157801. The reversal of 198157789 is 987751891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 191822500 + 6335289 = 13850^2 + 2517^2 .

It is a cyclic number.

It is not a de Polignac number, because 198157789 - 2⁹ = 198157277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198157709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99078894 + 99078895.

It is an arithmetic number, because the mean of its divisors is an integer number (99078895).

Almost surely, 2^198157789 is an apocalyptic number.

It is an amenable number.

198157789 is a deficient number, since it is larger than the sum of its proper divisors (1).

198157789 is an equidigital number, since it uses as much as digits as its factorization.

198157789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1270080, while the sum is 55.

The square root of 198157789 is about 14076.8529508552. The cubic root of 198157789 is about 583.0024537319.

The spelling of 198157789 in words is "one hundred ninety-eight million, one hundred fifty-seven thousand, seven hundred eighty-nine".