21643126 has 8 divisors (see below), whose sum is σ = 32519160. Its totient is φ = 10803408.

The previous prime is 21643117. The next prime is 21643129. The reversal of 21643126 is 62134612.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21643126.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21643129) 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, 7536 + ... + 10003.

It is an arithmetic number, because the mean of its divisors is an integer number (4064895).

Almost surely, 2^21643126 is an apocalyptic number.

21643126 is a deficient number, since it is larger than the sum of its proper divisors (10876034).

21643126 is a wasteful number, since it uses less digits than its factorization.

21643126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18158.

The product of its digits is 1728, while the sum is 25.

The square root of 21643126 is about 4652.2173208052. The cubic root of 21643126 is about 278.6805523199.

Adding to 21643126 its reverse (62134612), we get a palindrome (83777738).

The spelling of 21643126 in words is "twenty-one million, six hundred forty-three thousand, one hundred twenty-six".