21259323 has 6 divisors (see below), whose sum is σ = 30707924. Its totient is φ = 14172876.

The previous prime is 21259321. The next prime is 21259327. The reversal of 21259323 is 32395212.

It is not a de Polignac number, because 21259323 - 2¹ = 21259321 is a prime.

It is a super-4 number, since 4×21259323⁴ (a number of 30 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21259321) 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 in 5 ways as a sum of consecutive naturals, for example, 1181065 + ... + 1181082.

Almost surely, 2^21259323 is an apocalyptic number.

21259323 is a deficient number, since it is larger than the sum of its proper divisors (9448601).

21259323 is a wasteful number, since it uses less digits than its factorization.

21259323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2362153 (or 2362150 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 21259323 is about 4610.7833390868. The cubic root of 21259323 is about 277.0234137655.

The spelling of 21259323 in words is "twenty-one million, two hundred fifty-nine thousand, three hundred twenty-three".