21327243 has 16 divisors (see below), whose sum is σ = 32583936. Its totient is φ = 12155040.

The previous prime is 21327227. The next prime is 21327259. The reversal of 21327243 is 34272312.

It is an interprime number because it is at equal distance from previous prime (21327227) and next prime (21327259).

It is not a de Polignac number, because 21327243 - 2⁴ = 21327227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21327203) 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 15 ways as a sum of consecutive naturals, for example, 8580 + ... + 10782.

It is an arithmetic number, because the mean of its divisors is an integer number (2036496).

Almost surely, 2^21327243 is an apocalyptic number.

21327243 is a deficient number, since it is larger than the sum of its proper divisors (11256693).

21327243 is a wasteful number, since it uses less digits than its factorization.

21327243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2674.

The product of its digits is 2016, while the sum is 24.

The square root of 21327243 is about 4618.1428085325. The cubic root of 21327243 is about 277.3181147203.

Adding to 21327243 its reverse (34272312), we get a palindrome (55599555).

The spelling of 21327243 in words is "twenty-one million, three hundred twenty-seven thousand, two hundred forty-three".