199615813 has 2 divisors, whose sum is σ = 199615814. Its totient is φ = 199615812.

The previous prime is 199615771. The next prime is 199615837. The reversal of 199615813 is 318516991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171557604 + 28058209 = 13098^2 + 5297^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199615813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199615813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199618813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99807906 + 99807907.

It is an arithmetic number, because the mean of its divisors is an integer number (99807907).

Almost surely, 2^199615813 is an apocalyptic number.

It is an amenable number.

199615813 is a deficient number, since it is larger than the sum of its proper divisors (1).

199615813 is an equidigital number, since it uses as much as digits as its factorization.

199615813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58320, while the sum is 43.

The square root of 199615813 is about 14128.5460327664. The cubic root of 199615813 is about 584.4288510832.

The spelling of 199615813 in words is "one hundred ninety-nine million, six hundred fifteen thousand, eight hundred thirteen".