199942387 has 2 divisors, whose sum is σ = 199942388. Its totient is φ = 199942386.

The previous prime is 199942373. The next prime is 199942397. The reversal of 199942387 is 783249991.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (783249991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199942387 - 2²³ = 191553779 is a prime.

It is not a weakly prime, because it can be changed into another prime (199942367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99971193 + 99971194.

It is an arithmetic number, because the mean of its divisors is an integer number (99971194).

Almost surely, 2^199942387 is an apocalyptic number.

199942387 is a deficient number, since it is larger than the sum of its proper divisors (1).

199942387 is an equidigital number, since it uses as much as digits as its factorization.

199942387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 979776, while the sum is 52.

The square root of 199942387 is about 14140.0985498687. The cubic root of 199942387 is about 584.7473884384.

The spelling of 199942387 in words is "one hundred ninety-nine million, nine hundred forty-two thousand, three hundred eighty-seven".