21366453 has 16 divisors (see below), whose sum is σ = 29336832. Its totient is φ = 13824000.

The previous prime is 21366407. The next prime is 21366463. The reversal of 21366453 is 35466312.

It is not a de Polignac number, because 21366453 - 2⁸ = 21366197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21366453.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21366403) 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 15 ways as a sum of consecutive naturals, for example, 33013 + ... + 33653.

It is an arithmetic number, because the mean of its divisors is an integer number (1833552).

Almost surely, 2^21366453 is an apocalyptic number.

It is an amenable number.

21366453 is a deficient number, since it is larger than the sum of its proper divisors (7970379).

21366453 is a wasteful number, since it uses less digits than its factorization.

21366453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 956.

The product of its digits is 12960, while the sum is 30.

The square root of 21366453 is about 4622.3860721493. The cubic root of 21366453 is about 277.4879598704.

It can be divided in two parts, 213 and 66453, that added together give a palindrome (66666).

The spelling of 21366453 in words is "twenty-one million, three hundred sixty-six thousand, four hundred fifty-three".