21293263 has 2 divisors, whose sum is σ = 21293264. Its totient is φ = 21293262.

The previous prime is 21293257. The next prime is 21293273. The reversal of 21293263 is 36239212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21293263 - 2⁹ = 21292751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21293273) 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, 10646631 + 10646632.

It is an arithmetic number, because the mean of its divisors is an integer number (10646632).

Almost surely, 2^21293263 is an apocalyptic number.

21293263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21293263 is an equidigital number, since it uses as much as digits as its factorization.

21293263 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 28.

The square root of 21293263 is about 4614.4623738850. The cubic root of 21293263 is about 277.1707557990.

The spelling of 21293263 in words is "twenty-one million, two hundred ninety-three thousand, two hundred sixty-three".