21243319 has 8 divisors (see below), whose sum is σ = 22578048. Its totient is φ = 19918080.

The previous prime is 21243307. The next prime is 21243331. The reversal of 21243319 is 91334212.

It is an interprime number because it is at equal distance from previous prime (21243307) and next prime (21243331).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21243319 - 2⁹ = 21242807 is a prime.

It is a super-2 number, since 2×21243319² = 902557204271522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21243293 and 21243302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243359) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2554 + ... + 7000.

It is an arithmetic number, because the mean of its divisors is an integer number (2822256).

Almost surely, 2^21243319 is an apocalyptic number.

21243319 is a deficient number, since it is larger than the sum of its proper divisors (1334729).

21243319 is a wasteful number, since it uses less digits than its factorization.

21243319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4745.

The product of its digits is 1296, while the sum is 25.

The square root of 21243319 is about 4609.0475154852. The cubic root of 21243319 is about 276.9538819858.

The spelling of 21243319 in words is "twenty-one million, two hundred forty-three thousand, three hundred nineteen".