21032447 has 2 divisors, whose sum is σ = 21032448. Its totient is φ = 21032446.

The previous prime is 21032441. The next prime is 21032471. The reversal of 21032447 is 74423012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21032447 - 2¹⁸ = 20770303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21032441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10516223 + 10516224.

It is an arithmetic number, because the mean of its divisors is an integer number (10516224).

Almost surely, 2^21032447 is an apocalyptic number.

21032447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21032447 is an equidigital number, since it uses as much as digits as its factorization.

21032447 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21032447 is about 4586.1145864446. The cubic root of 21032447 is about 276.0344378719.

Adding to 21032447 its reverse (74423012), we get a palindrome (95455459).

The spelling of 21032447 in words is "twenty-one million, thirty-two thousand, four hundred forty-seven".