21422247 has 16 divisors (see below), whose sum is σ = 35611392. Its totient is φ = 11128320.

The previous prime is 21422231. The next prime is 21422273. The reversal of 21422247 is 74222412.

It is not a de Polignac number, because 21422247 - 2⁴ = 21422231 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21422347) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46138 + ... + 46599.

It is an arithmetic number, because the mean of its divisors is an integer number (2225712).

Almost surely, 2^21422247 is an apocalyptic number.

21422247 is a deficient number, since it is larger than the sum of its proper divisors (14189145).

21422247 is a wasteful number, since it uses less digits than its factorization.

21422247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92758.

The product of its digits is 1792, while the sum is 24.

The square root of 21422247 is about 4628.4173320910. The cubic root of 21422247 is about 277.7292837597.

Adding to 21422247 its reverse (74222412), we get a palindrome (95644659).

The spelling of 21422247 in words is "twenty-one million, four hundred twenty-two thousand, two hundred forty-seven".