21829243 has 4 divisors (see below), whose sum is σ = 21842568. Its totient is φ = 21815920.

The previous prime is 21829217. The next prime is 21829253. The reversal of 21829243 is 34292812.

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 21829243 - 2⁵ = 21829211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21829253) 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, 3793 + ... + 7618.

It is an arithmetic number, because the mean of its divisors is an integer number (5460642).

Almost surely, 2^21829243 is an apocalyptic number.

21829243 is a deficient number, since it is larger than the sum of its proper divisors (13325).

21829243 is a wasteful number, since it uses less digits than its factorization.

21829243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13324.

The product of its digits is 6912, while the sum is 31.

The square root of 21829243 is about 4672.1775437156. The cubic root of 21829243 is about 279.4770980645.

The spelling of 21829243 in words is "twenty-one million, eight hundred twenty-nine thousand, two hundred forty-three".