21864934 has 32 divisors (see below), whose sum is σ = 42497280. Its totient is φ = 8193312.

The previous prime is 21864923. The next prime is 21864959. The reversal of 21864934 is 43946812.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21864893 and 21864902.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 297 + ... + 6619.

It is an arithmetic number, because the mean of its divisors is an integer number (1328040).

Almost surely, 2^21864934 is an apocalyptic number.

21864934 is a deficient number, since it is larger than the sum of its proper divisors (20632346).

21864934 is a wasteful number, since it uses less digits than its factorization.

21864934 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6364.

The product of its digits is 41472, while the sum is 37.

The square root of 21864934 is about 4675.9955089799. The cubic root of 21864934 is about 279.6293309467.

The spelling of 21864934 in words is "twenty-one million, eight hundred sixty-four thousand, nine hundred thirty-four".