199121851 has 2 divisors, whose sum is σ = 199121852. Its totient is φ = 199121850.

The previous prime is 199121821. The next prime is 199121869. The reversal of 199121851 is 158121991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 199121851 - 2⁷ = 199121723 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199121851.

It is not a weakly prime, because it can be changed into another prime (199121821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99560925 + 99560926.

It is an arithmetic number, because the mean of its divisors is an integer number (99560926).

Almost surely, 2^199121851 is an apocalyptic number.

199121851 is a deficient number, since it is larger than the sum of its proper divisors (1).

199121851 is an equidigital number, since it uses as much as digits as its factorization.

199121851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 37.

The square root of 199121851 is about 14111.0542129212. The cubic root of 199121851 is about 583.9463841361.

The spelling of 199121851 in words is "one hundred ninety-nine million, one hundred twenty-one thousand, eight hundred fifty-one".