199969961 has 2 divisors, whose sum is σ = 199969962. Its totient is φ = 199969960.

The previous prime is 199969919. The next prime is 199969967. The reversal of 199969961 is 169969991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186049600 + 13920361 = 13640^2 + 3731^2 .

It is a cyclic number.

It is not a de Polignac number, because 199969961 - 2⁶ = 199969897 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199969961.

It is not a weakly prime, because it can be changed into another prime (199969967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99984980 + 99984981.

It is an arithmetic number, because the mean of its divisors is an integer number (99984981).

Almost surely, 2^199969961 is an apocalyptic number.

It is an amenable number.

199969961 is a deficient number, since it is larger than the sum of its proper divisors (1).

199969961 is an equidigital number, since it uses as much as digits as its factorization.

199969961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2125764, while the sum is 59.

The square root of 199969961 is about 14141.0735448197. The cubic root of 199969961 is about 584.7742679870.

The spelling of 199969961 in words is "one hundred ninety-nine million, nine hundred sixty-nine thousand, nine hundred sixty-one".