199674124921 has 2 divisors, whose sum is σ = 199674124922. Its totient is φ = 199674124920.

The previous prime is 199674124883. The next prime is 199674124931. The reversal of 199674124921 is 129421476991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 199394399296 + 279725625 = 446536^2 + 16725^2 .

It is a cyclic number.

It is not a de Polignac number, because 199674124921 - 2¹¹ = 199674122873 is a prime.

It is a super-2 number, since 2×199674124921² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (199674124931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99837062460 + 99837062461.

It is an arithmetic number, because the mean of its divisors is an integer number (99837062461).

Almost surely, 2^199674124921 is an apocalyptic number.

It is an amenable number.

199674124921 is a deficient number, since it is larger than the sum of its proper divisors (1).

199674124921 is an equidigital number, since it uses as much as digits as its factorization.

199674124921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1959552, while the sum is 55.

The spelling of 199674124921 in words is "one hundred ninety-nine billion, six hundred seventy-four million, one hundred twenty-four thousand, nine hundred twenty-one".