21846321 has 16 divisors (see below), whose sum is σ = 36988800. Its totient is φ = 12483504.

The previous prime is 21846311. The next prime is 21846323. The reversal of 21846321 is 12364812.

21846321 is a `hidden beast` number, since 21 + 8 + 4 + 632 + 1 = 666.

It is not a de Polignac number, because 21846321 - 2⁹ = 21845809 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 (21846323) 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, 57606 + ... + 57983.

It is an arithmetic number, because the mean of its divisors is an integer number (2311800).

Almost surely, 2^21846321 is an apocalyptic number.

21846321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21846321 is a deficient number, since it is larger than the sum of its proper divisors (15142479).

21846321 is a wasteful number, since it uses less digits than its factorization.

21846321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115605 (or 115599 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 21846321 is about 4674.0048138614. The cubic root of 21846321 is about 279.5499615735.

The spelling of 21846321 in words is "twenty-one million, eight hundred forty-six thousand, three hundred twenty-one".