21447533 has 2 divisors, whose sum is σ = 21447534. Its totient is φ = 21447532.

The previous prime is 21447527. The next prime is 21447541. The reversal of 21447533 is 33574412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20097289 + 1350244 = 4483^2 + 1162^2 .

It is a cyclic number.

It is not a de Polignac number, because 21447533 - 2⁸ = 21447277 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21447496 and 21447505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21447593) 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 as a sum of consecutive naturals, namely, 10723766 + 10723767.

It is an arithmetic number, because the mean of its divisors is an integer number (10723767).

Almost surely, 2^21447533 is an apocalyptic number.

It is an amenable number.

21447533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21447533 is an equidigital number, since it uses as much as digits as its factorization.

21447533 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 29.

The square root of 21447533 is about 4631.1481297838. The cubic root of 21447533 is about 277.8385144640.

The spelling of 21447533 in words is "twenty-one million, four hundred forty-seven thousand, five hundred thirty-three".