21124219 has 4 divisors (see below), whose sum is σ = 22236040. Its totient is φ = 20012400.

The previous prime is 21124199. The next prime is 21124253. The reversal of 21124219 is 91242112.

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 21124219 - 2¹⁵ = 21091451 is a prime.

It is a super-2 number, since 2×21124219² = 892465256719922, 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 21124219.

It is not an unprimeable number, because it can be changed into a prime (21124289) 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, 555882 + ... + 555919.

It is an arithmetic number, because the mean of its divisors is an integer number (5559010).

Almost surely, 2^21124219 is an apocalyptic number.

21124219 is a deficient number, since it is larger than the sum of its proper divisors (1111821).

21124219 is a wasteful number, since it uses less digits than its factorization.

21124219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111820.

The product of its digits is 288, while the sum is 22.

The square root of 21124219 is about 4596.1091153279. The cubic root of 21124219 is about 276.4353339570.

The spelling of 21124219 in words is "twenty-one million, one hundred twenty-four thousand, two hundred nineteen".