199969421 has 2 divisors, whose sum is σ = 199969422. Its totient is φ = 199969420.

The previous prime is 199969409. The next prime is 199969439. The reversal of 199969421 is 124969991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164994025 + 34975396 = 12845^2 + 5914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199969421 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199969421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199969481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99984710 + 99984711.

It is an arithmetic number, because the mean of its divisors is an integer number (99984711).

Almost surely, 2^199969421 is an apocalyptic number.

It is an amenable number.

199969421 is a deficient number, since it is larger than the sum of its proper divisors (1).

199969421 is an equidigital number, since it uses as much as digits as its factorization.

199969421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 314928, while the sum is 50.

The square root of 199969421 is about 14141.0544514898. The cubic root of 199969421 is about 584.7737416107.

The spelling of 199969421 in words is "one hundred ninety-nine million, nine hundred sixty-nine thousand, four hundred twenty-one".