199280021 has 2 divisors, whose sum is σ = 199280022. Its totient is φ = 199280020.

The previous prime is 199280009. The next prime is 199280057. The reversal of 199280021 is 120082991.

It is a happy number.

199280021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129640996 + 69639025 = 11386^2 + 8345^2 .

It is a cyclic number.

It is not a de Polignac number, because 199280021 - 2⁶ = 199279957 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 199280021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199280071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99640010 + 99640011.

It is an arithmetic number, because the mean of its divisors is an integer number (99640011).

Almost surely, 2^199280021 is an apocalyptic number.

It is an amenable number.

199280021 is a deficient number, since it is larger than the sum of its proper divisors (1).

199280021 is an equidigital number, since it uses as much as digits as its factorization.

199280021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 199280021 is about 14116.6575718192. The cubic root of 199280021 is about 584.1009600974.

The spelling of 199280021 in words is "one hundred ninety-nine million, two hundred eighty thousand, twenty-one".