21864434 has 16 divisors (see below), whose sum is σ = 34041600. Its totient is φ = 10519824.

The previous prime is 21864407. The next prime is 21864443. The reversal of 21864434 is 43446812.

It is a self number, because there is not a number n which added to its sum of digits gives 21864434.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27389 + ... + 28175.

It is an arithmetic number, because the mean of its divisors is an integer number (2127600).

Almost surely, 2^21864434 is an apocalyptic number.

21864434 is a deficient number, since it is larger than the sum of its proper divisors (12177166).

21864434 is a wasteful number, since it uses less digits than its factorization.

21864434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1297.

The product of its digits is 18432, while the sum is 32.

The square root of 21864434 is about 4675.9420441233. The cubic root of 21864434 is about 279.6271994405.

The spelling of 21864434 in words is "twenty-one million, eight hundred sixty-four thousand, four hundred thirty-four".