163839987 has 12 divisors (see below), whose sum is σ = 236829840. Its totient is φ = 109147248.

The previous prime is 163839967. The next prime is 163840007. The reversal of 163839987 is 789938361.

It is an interprime number because it is at equal distance from previous prime (163839967) and next prime (163840007).

It is not a de Polignac number, because 163839987 - 2¹⁰ = 163838963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (163839967) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8193 + ... + 19869.

It is an arithmetic number, because the mean of its divisors is an integer number (19735820).

Almost surely, 2^163839987 is an apocalyptic number.

163839987 is a deficient number, since it is larger than the sum of its proper divisors (72989853).

163839987 is a wasteful number, since it uses less digits than its factorization.

163839987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13242 (or 13239 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 54.

The square root of 163839987 is about 12799.9994921875. Note that the first 3 decimals coincide. The cubic root of 163839987 is about 547.1922884641.

The spelling of 163839987 in words is "one hundred sixty-three million, eight hundred thirty-nine thousand, nine hundred eighty-seven".