21422647 has 8 divisors (see below), whose sum is σ = 22208256. Its totient is φ = 20650872.

The previous prime is 21422641. The next prime is 21422689. The reversal of 21422647 is 74622412.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21422647 - 2²³ = 13034039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21422641) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 253 + ... + 6550.

It is an arithmetic number, because the mean of its divisors is an integer number (2776032).

Almost surely, 2^21422647 is an apocalyptic number.

21422647 is a deficient number, since it is larger than the sum of its proper divisors (785609).

21422647 is an equidigital number, since it uses as much as digits as its factorization.

21422647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6917.

The product of its digits is 5376, while the sum is 28.

The square root of 21422647 is about 4628.4605432044. The cubic root of 21422647 is about 277.7310123524.

The spelling of 21422647 in words is "twenty-one million, four hundred twenty-two thousand, six hundred forty-seven".