163878409 has 2 divisors, whose sum is σ = 163878410. Its totient is φ = 163878408.

The previous prime is 163878397. The next prime is 163878413. The reversal of 163878409 is 904878361.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162486009 + 1392400 = 12747^2 + 1180^2 .

It is an emirp because it is prime and its reverse (904878361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 163878409 - 2⁹ = 163877897 is a prime.

It is a super-2 number, since 2×163878409² = 53712265872742562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (163878479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81939204 + 81939205.

It is an arithmetic number, because the mean of its divisors is an integer number (81939205).

Almost surely, 2^163878409 is an apocalyptic number.

It is an amenable number.

163878409 is a deficient number, since it is larger than the sum of its proper divisors (1).

163878409 is an equidigital number, since it uses as much as digits as its factorization.

163878409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 163878409 is about 12801.5002636410. The cubic root of 163878409 is about 547.2350590137.

The spelling of 163878409 in words is "one hundred sixty-three million, eight hundred seventy-eight thousand, four hundred nine".