199089661 has 2 divisors, whose sum is σ = 199089662. Its totient is φ = 199089660.

The previous prime is 199089647. The next prime is 199089673. The reversal of 199089661 is 166980991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136188900 + 62900761 = 11670^2 + 7931^2 .

It is an emirp because it is prime and its reverse (166980991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199089661 - 2¹³ = 199081469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199089061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99544830 + 99544831.

It is an arithmetic number, because the mean of its divisors is an integer number (99544831).

Almost surely, 2^199089661 is an apocalyptic number.

It is an amenable number.

199089661 is a deficient number, since it is larger than the sum of its proper divisors (1).

199089661 is an equidigital number, since it uses as much as digits as its factorization.

199089661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 209952, while the sum is 49.

The square root of 199089661 is about 14109.9135716701. The cubic root of 199089661 is about 583.9149155537.

The spelling of 199089661 in words is "one hundred ninety-nine million, eighty-nine thousand, six hundred sixty-one".