21384263 has 2 divisors, whose sum is σ = 21384264. Its totient is φ = 21384262.

The previous prime is 21384257. The next prime is 21384289. The reversal of 21384263 is 36248312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21384263 - 2¹⁰ = 21383239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21384763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10692131 + 10692132.

It is an arithmetic number, because the mean of its divisors is an integer number (10692132).

Almost surely, 2^21384263 is an apocalyptic number.

21384263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21384263 is an equidigital number, since it uses as much as digits as its factorization.

21384263 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 29.

The square root of 21384263 is about 4624.3121650684. The cubic root of 21384263 is about 277.5650384579.

The spelling of 21384263 in words is "twenty-one million, three hundred eighty-four thousand, two hundred sixty-three".