21422347 has 2 divisors, whose sum is σ = 21422348. Its totient is φ = 21422346.

The previous prime is 21422341. The next prime is 21422381. The reversal of 21422347 is 74322412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21422347 is a prime.

It is not a weakly prime, because it can be changed into another prime (21422341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711173 + 10711174.

It is an arithmetic number, because the mean of its divisors is an integer number (10711174).

Almost surely, 2^21422347 is an apocalyptic number.

21422347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422347 is an equidigital number, since it uses as much as digits as its factorization.

21422347 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 25.

The square root of 21422347 is about 4628.4281349071. The cubic root of 21422347 is about 277.7297159099.

Adding to 21422347 its reverse (74322412), we get a palindrome (95744759).

It can be divided in two parts, 2142 and 2347, that added together give a square (4489 = 67²).

The spelling of 21422347 in words is "twenty-one million, four hundred twenty-two thousand, three hundred forty-seven".