21452747 has 2 divisors, whose sum is σ = 21452748. Its totient is φ = 21452746.

The previous prime is 21452741. The next prime is 21452749. The reversal of 21452747 is 74725412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21452747 - 2⁴ = 21452731 is a prime.

Together with 21452749, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (21452741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10726373 + 10726374.

It is an arithmetic number, because the mean of its divisors is an integer number (10726374).

Almost surely, 2^21452747 is an apocalyptic number.

21452747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21452747 is an equidigital number, since it uses as much as digits as its factorization.

21452747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15680, while the sum is 32.

The square root of 21452747 is about 4631.7110229374. The cubic root of 21452747 is about 277.8610272730.

The spelling of 21452747 in words is "twenty-one million, four hundred fifty-two thousand, seven hundred forty-seven".