21522263 has 16 divisors (see below), whose sum is σ = 25730880. Its totient is φ = 17611776.

The previous prime is 21522257. The next prime is 21522283. The reversal of 21522263 is 36222512.

It is not a de Polignac number, because 21522263 - 2¹⁶ = 21456727 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21522223) 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 in 15 ways as a sum of consecutive naturals, for example, 19145 + ... + 20237.

It is an arithmetic number, because the mean of its divisors is an integer number (1608180).

Almost surely, 2^21522263 is an apocalyptic number.

21522263 is a deficient number, since it is larger than the sum of its proper divisors (4208617).

21522263 is a wasteful number, since it uses less digits than its factorization.

21522263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1226.

The product of its digits is 1440, while the sum is 23.

The square root of 21522263 is about 4639.2093076299. The cubic root of 21522263 is about 278.1608328700.

Adding to 21522263 its reverse (36222512), we get a palindrome (57744775).

The spelling of 21522263 in words is "twenty-one million, five hundred twenty-two thousand, two hundred sixty-three".