198897771 has 12 divisors (see below), whose sum is σ = 269112248. Its totient is φ = 130644864.

The previous prime is 198897733. The next prime is 198897779. The reversal of 198897771 is 177798891.

It is not a de Polignac number, because 198897771 - 2¹⁵ = 198865003 is a prime.

It is a Duffinian number.

Its product of digits (1778112) is a multiple of the sum of its prime divisors (1029).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198897779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 208231 + ... + 209183.

Almost surely, 2^198897771 is an apocalyptic number.

198897771 is a deficient number, since it is larger than the sum of its proper divisors (70214477).

198897771 is an frugal number, since it uses more digits than its factorization.

198897771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1982 (or 1029 counting only the distinct ones).

The product of its digits is 1778112, while the sum is 57.

The square root of 198897771 is about 14103.1121033622. The cubic root of 198897771 is about 583.7272556314.

The spelling of 198897771 in words is "one hundred ninety-eight million, eight hundred ninety-seven thousand, seven hundred seventy-one".