198905690 has 16 divisors (see below), whose sum is σ = 358254792. Its totient is φ = 79512384.

The previous prime is 198905621. The next prime is 198905711. The reversal of 198905690 is 96509891.

It can be written as a sum of positive squares in 4 ways, for example, as 115713049 + 83192641 = 10757^2 + 9121^2 .

It is a super-2 number, since 2×198905690² = 79126947028752200, which contains 22 as substring.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 13472 + ... + 24068.

Almost surely, 2^198905690 is an apocalyptic number.

198905690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

198905690 is a deficient number, since it is larger than the sum of its proper divisors (159349102).

198905690 is a wasteful number, since it uses less digits than its factorization.

198905690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12481.

The product of its (nonzero) digits is 174960, while the sum is 47.

The square root of 198905690 is about 14103.3928542036. The cubic root of 198905690 is about 583.7350024499.

The spelling of 198905690 in words is "one hundred ninety-eight million, nine hundred five thousand, six hundred ninety".