21326463 has 16 divisors (see below), whose sum is σ = 31683840. Its totient is φ = 14177592.

The previous prime is 21326441. The next prime is 21326477. The reversal of 21326463 is 36462312.

21326463 is a `hidden beast` number, since 2 + 13 + 2 + 646 + 3 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21326463 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21326413) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11070 + ... + 12852.

It is an arithmetic number, because the mean of its divisors is an integer number (1980240).

Almost surely, 2^21326463 is an apocalyptic number.

21326463 is a deficient number, since it is larger than the sum of its proper divisors (10357377).

21326463 is a wasteful number, since it uses less digits than its factorization.

21326463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2235 (or 2229 counting only the distinct ones).

The product of its digits is 5184, while the sum is 27.

The square root of 21326463 is about 4618.0583582281. The cubic root of 21326463 is about 277.3147338994.

Adding to 21326463 its reverse (36462312), we get a palindrome (57788775).

The spelling of 21326463 in words is "twenty-one million, three hundred twenty-six thousand, four hundred sixty-three".