21267319 has 4 divisors (see below), whose sum is σ = 21385000. Its totient is φ = 21149640.

The previous prime is 21267263. The next prime is 21267371. The reversal of 21267319 is 91376212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21267319 - 2⁹ = 21266807 is a prime.

It is a super-2 number, since 2×21267319² = 904597714895522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21267619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58569 + ... + 58930.

It is an arithmetic number, because the mean of its divisors is an integer number (5346250).

Almost surely, 2^21267319 is an apocalyptic number.

21267319 is a deficient number, since it is larger than the sum of its proper divisors (117681).

21267319 is a wasteful number, since it uses less digits than its factorization.

21267319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117680.

The product of its digits is 4536, while the sum is 31.

The square root of 21267319 is about 4611.6503553500. The cubic root of 21267319 is about 277.0581405151.

The spelling of 21267319 in words is "twenty-one million, two hundred sixty-seven thousand, three hundred nineteen".