163989399 has 16 divisors (see below), whose sum is σ = 263041280. Its totient is φ = 88776000.

The previous prime is 163989389. The next prime is 163989407. The reversal of 163989399 is 993989361.

It is not a de Polignac number, because 163989399 - 2⁴ = 163989383 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163989359) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 205102 + ... + 205899.

It is an arithmetic number, because the mean of its divisors is an integer number (16440080).

Almost surely, 2^163989399 is an apocalyptic number.

163989399 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

163989399 is a deficient number, since it is larger than the sum of its proper divisors (99051881).

163989399 is a wasteful number, since it uses less digits than its factorization.

163989399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411030.

The product of its digits is 2834352, while the sum is 57.

The square root of 163989399 is about 12805.8345686644. The cubic root of 163989399 is about 547.3585731744.

The spelling of 163989399 in words is "one hundred sixty-three million, nine hundred eighty-nine thousand, three hundred ninety-nine".