199994521 has 2 divisors, whose sum is σ = 199994522. Its totient is φ = 199994520.

The previous prime is 199994489. The next prime is 199994533. The reversal of 199994521 is 125499991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 196308121 + 3686400 = 14011^2 + 1920^2 .

It is a cyclic number.

It is not a de Polignac number, because 199994521 - 2⁵ = 199994489 is a prime.

It is not a weakly prime, because it can be changed into another prime (199994581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99997260 + 99997261.

It is an arithmetic number, because the mean of its divisors is an integer number (99997261).

Almost surely, 2^199994521 is an apocalyptic number.

It is an amenable number.

199994521 is a deficient number, since it is larger than the sum of its proper divisors (1).

199994521 is an equidigital number, since it uses as much as digits as its factorization.

199994521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 262440, while the sum is 49.

The square root of 199994521 is about 14141.9419105015. The cubic root of 199994521 is about 584.7982073627.

The spelling of 199994521 in words is "one hundred ninety-nine million, nine hundred ninety-four thousand, five hundred twenty-one".