199121807 has 2 divisors, whose sum is σ = 199121808. Its totient is φ = 199121806.

The previous prime is 199121759. The next prime is 199121821. The reversal of 199121807 is 708121991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 199121807 - 2⁸ = 199121551 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199121107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99560903 + 99560904.

It is an arithmetic number, because the mean of its divisors is an integer number (99560904).

Almost surely, 2^199121807 is an apocalyptic number.

199121807 is a deficient number, since it is larger than the sum of its proper divisors (1).

199121807 is an equidigital number, since it uses as much as digits as its factorization.

199121807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 38.

The square root of 199121807 is about 14111.0526538597. The cubic root of 199121807 is about 583.9463411245.

The spelling of 199121807 in words is "one hundred ninety-nine million, one hundred twenty-one thousand, eight hundred seven".