199121961539 has 2 divisors, whose sum is σ = 199121961540. Its totient is φ = 199121961538.

The previous prime is 199121961527. The next prime is 199121961557. The reversal of 199121961539 is 935169121991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199121961539 - 2⁴ = 199121961523 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (199121960539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99560980769 + 99560980770.

It is an arithmetic number, because the mean of its divisors is an integer number (99560980770).

Almost surely, 2^199121961539 is an apocalyptic number.

199121961539 is a deficient number, since it is larger than the sum of its proper divisors (1).

199121961539 is an equidigital number, since it uses as much as digits as its factorization.

199121961539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1180980, while the sum is 56.

The spelling of 199121961539 in words is "one hundred ninety-nine billion, one hundred twenty-one million, nine hundred sixty-one thousand, five hundred thirty-nine".