199851551 has 2 divisors, whose sum is σ = 199851552. Its totient is φ = 199851550.

The previous prime is 199851539. The next prime is 199851563. The reversal of 199851551 is 155158991.

It is a balanced prime because it is at equal distance from previous prime (199851539) and next prime (199851563).

It is a cyclic number.

It is not a de Polignac number, because 199851551 - 2¹⁰ = 199850527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199851571) 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, 99925775 + 99925776.

It is an arithmetic number, because the mean of its divisors is an integer number (99925776).

Almost surely, 2^199851551 is an apocalyptic number.

199851551 is a deficient number, since it is larger than the sum of its proper divisors (1).

199851551 is an equidigital number, since it uses as much as digits as its factorization.

199851551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81000, while the sum is 44.

The square root of 199851551 is about 14136.8861847296. The cubic root of 199851551 is about 584.6588226598.

The spelling of 199851551 in words is "one hundred ninety-nine million, eight hundred fifty-one thousand, five hundred fifty-one".