168509399 has 2 divisors, whose sum is σ = 168509400. Its totient is φ = 168509398.

The previous prime is 168509387. The next prime is 168509413. The reversal of 168509399 is 993905861.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168509399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168529399) 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, 84254699 + 84254700.

It is an arithmetic number, because the mean of its divisors is an integer number (84254700).

Almost surely, 2^168509399 is an apocalyptic number.

168509399 is a deficient number, since it is larger than the sum of its proper divisors (1).

168509399 is an equidigital number, since it uses as much as digits as its factorization.

168509399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 524880, while the sum is 50.

The square root of 168509399 is about 12981.1170166515. The cubic root of 168509399 is about 552.3419682747.

The spelling of 168509399 in words is "one hundred sixty-eight million, five hundred nine thousand, three hundred ninety-nine".