163860021 has 24 divisors (see below), whose sum is σ = 255394776. Its totient is φ = 100638720.

The previous prime is 163860007. The next prime is 163860023. The reversal of 163860021 is 120068361.

163860021 is a `hidden beast` number, since 1 + 6 + 38 + 600 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 378225 + 163481796 = 615^2 + 12786^2 .

It is not a de Polignac number, because 163860021 - 2⁵ = 163859989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163860023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 77701 + ... + 79781.

It is an arithmetic number, because the mean of its divisors is an integer number (10641449).

Almost surely, 2^163860021 is an apocalyptic number.

It is an amenable number.

163860021 is a deficient number, since it is larger than the sum of its proper divisors (91534755).

163860021 is a wasteful number, since it uses less digits than its factorization.

163860021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2773 (or 2770 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 163860021 is about 12800.7820464220. The cubic root of 163860021 is about 547.2145907191.

The spelling of 163860021 in words is "one hundred sixty-three million, eight hundred sixty thousand, twenty-one".