21159171 has 32 divisors (see below), whose sum is σ = 34467840. Its totient is φ = 12722400.

The previous prime is 21159163. The next prime is 21159181. The reversal of 21159171 is 17195112.

21159171 is a `hidden beast` number, since 2 + 1 + 1 + 591 + 71 = 666.

It is not a de Polignac number, because 21159171 - 2³ = 21159163 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21159121) 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 in 31 ways as a sum of consecutive naturals, for example, 56541 + ... + 56913.

It is an arithmetic number, because the mean of its divisors is an integer number (1077120).

Almost surely, 2^21159171 is an apocalyptic number.

21159171 is a deficient number, since it is larger than the sum of its proper divisors (13308669).

21159171 is a wasteful number, since it uses less digits than its factorization.

21159171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584 (or 578 counting only the distinct ones).

The product of its digits is 630, while the sum is 27.

The square root of 21159171 is about 4599.9098904218. The cubic root of 21159171 is about 276.5877126684.

The spelling of 21159171 in words is "twenty-one million, one hundred fifty-nine thousand, one hundred seventy-one".