21313219 has 4 divisors (see below), whose sum is σ = 21674520. Its totient is φ = 20951920.

The previous prime is 21313207. The next prime is 21313241. The reversal of 21313219 is 91231312.

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 21313219 - 2⁷ = 21313091 is a prime.

It is a super-2 number, since 2×21313219² = 908506608283922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21313219.

It is not an unprimeable number, because it can be changed into a prime (21311219) 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, 180562 + ... + 180679.

It is an arithmetic number, because the mean of its divisors is an integer number (5418630).

Almost surely, 2^21313219 is an apocalyptic number.

21313219 is a deficient number, since it is larger than the sum of its proper divisors (361301).

21313219 is an equidigital number, since it uses as much as digits as its factorization.

21313219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361300.

The product of its digits is 324, while the sum is 22.

The square root of 21313219 is about 4616.6241995640. The cubic root of 21313219 is about 277.2573167072.

The spelling of 21313219 in words is "twenty-one million, three hundred thirteen thousand, two hundred nineteen".