21830865 has 32 divisors (see below), whose sum is σ = 40124160. Its totient is φ = 9928704.

The previous prime is 21830843. The next prime is 21830891. The reversal of 21830865 is 56803812.

It is a happy number.

It is not a de Polignac number, because 21830865 - 2⁶ = 21830801 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26581 + ... + 27389.

It is an arithmetic number, because the mean of its divisors is an integer number (1253880).

Almost surely, 2^21830865 is an apocalyptic number.

It is an amenable number.

21830865 is a deficient number, since it is larger than the sum of its proper divisors (18293295).

21830865 is a wasteful number, since it uses less digits than its factorization.

21830865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1081.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 21830865 is about 4672.3511212237. The cubic root of 21830865 is about 279.4840199815.

The spelling of 21830865 in words is "twenty-one million, eight hundred thirty thousand, eight hundred sixty-five".