21643422 has 8 divisors (see below), whose sum is σ = 43286856. Its totient is φ = 7214472.

The previous prime is 21643421. The next prime is 21643429. The reversal of 21643422 is 22434612.

It is a sphenic number, since it is the product of 3 distinct primes.

21643422 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21643392 and 21643401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21643421) 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, 1803613 + ... + 1803624.

It is an arithmetic number, because the mean of its divisors is an integer number (5410857).

Almost surely, 2^21643422 is an apocalyptic number.

21643422 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21643422 is a wasteful number, since it uses less digits than its factorization.

21643422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3607242.

The product of its digits is 2304, while the sum is 24.

The square root of 21643422 is about 4652.2491334837. The cubic root of 21643422 is about 278.6818227628.

The spelling of 21643422 in words is "twenty-one million, six hundred forty-three thousand, four hundred twenty-two".