199814921 has 2 divisors, whose sum is σ = 199814922. Its totient is φ = 199814920.

The previous prime is 199814917. The next prime is 199814969. The reversal of 199814921 is 129418991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 197009296 + 2805625 = 14036^2 + 1675^2 .

It is a cyclic number.

It is not a de Polignac number, because 199814921 - 2² = 199814917 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (199814221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99907460 + 99907461.

It is an arithmetic number, because the mean of its divisors is an integer number (99907461).

Almost surely, 2^199814921 is an apocalyptic number.

It is an amenable number.

199814921 is a deficient number, since it is larger than the sum of its proper divisors (1).

199814921 is an equidigital number, since it uses as much as digits as its factorization.

199814921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 44.

The square root of 199814921 is about 14135.5905783947. The cubic root of 199814921 is about 584.6231005432.

The spelling of 199814921 in words is "one hundred ninety-nine million, eight hundred fourteen thousand, nine hundred twenty-one".