21464447 has 2 divisors, whose sum is σ = 21464448. Its totient is φ = 21464446.

The previous prime is 21464423. The next prime is 21464449. The reversal of 21464447 is 74446412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21464447 - 2¹⁰ = 21463423 is a prime.

Together with 21464449, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21464449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10732223 + 10732224.

It is an arithmetic number, because the mean of its divisors is an integer number (10732224).

Almost surely, 2^21464447 is an apocalyptic number.

21464447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21464447 is an equidigital number, since it uses as much as digits as its factorization.

21464447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21504, while the sum is 32.

The square root of 21464447 is about 4632.9738829396. The cubic root of 21464447 is about 277.9115318103.

The spelling of 21464447 in words is "twenty-one million, four hundred sixty-four thousand, four hundred forty-seven".