21282743 has 2 divisors, whose sum is σ = 21282744. Its totient is φ = 21282742.

The previous prime is 21282739. The next prime is 21282761. The reversal of 21282743 is 34728212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21282743 - 2² = 21282739 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21282043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10641371 + 10641372.

It is an arithmetic number, because the mean of its divisors is an integer number (10641372).

Almost surely, 2^21282743 is an apocalyptic number.

21282743 is a deficient number, since it is larger than the sum of its proper divisors (1).

21282743 is an equidigital number, since it uses as much as digits as its factorization.

21282743 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5376, while the sum is 29.

The square root of 21282743 is about 4613.3223386189. The cubic root of 21282743 is about 277.1251026007.

The spelling of 21282743 in words is "twenty-one million, two hundred eighty-two thousand, seven hundred forty-three".