199961903291 has 2 divisors, whose sum is σ = 199961903292. Its totient is φ = 199961903290.

The previous prime is 199961903263. The next prime is 199961903321. The reversal of 199961903291 is 192309169991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199961903291 - 2¹⁴ = 199961886907 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199961903291.

It is not a weakly prime, because it can be changed into another prime (199961903891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99980951645 + 99980951646.

It is an arithmetic number, because the mean of its divisors is an integer number (99980951646).

Almost surely, 2^199961903291 is an apocalyptic number.

199961903291 is a deficient number, since it is larger than the sum of its proper divisors (1).

199961903291 is an equidigital number, since it uses as much as digits as its factorization.

199961903291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2125764, while the sum is 59.

The spelling of 199961903291 in words is "one hundred ninety-nine billion, nine hundred sixty-one million, nine hundred three thousand, two hundred ninety-one".