21226547 has 2 divisors, whose sum is σ = 21226548. Its totient is φ = 21226546.

The previous prime is 21226531. The next prime is 21226571. The reversal of 21226547 is 74562212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21226547 - 2⁴ = 21226531 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21226147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613273 + 10613274.

It is an arithmetic number, because the mean of its divisors is an integer number (10613274).

Almost surely, 2^21226547 is an apocalyptic number.

21226547 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226547 is an equidigital number, since it uses as much as digits as its factorization.

21226547 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 29.

The square root of 21226547 is about 4607.2276913563. The cubic root of 21226547 is about 276.8809760289.

Adding to 21226547 its reverse (74562212), we get a palindrome (95788759).

The spelling of 21226547 in words is "twenty-one million, two hundred twenty-six thousand, five hundred forty-seven".