21369453 has 16 divisors (see below), whose sum is σ = 32647680. Its totient is φ = 12179376.

The previous prime is 21369451. The next prime is 21369473. The reversal of 21369453 is 35496312.

21369453 is a nontrivial binomial coefficient, being equal to C(6538, 2).

It is not a de Polignac number, because 21369453 - 2¹ = 21369451 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21369451) 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, 8718 + ... + 10896.

It is an arithmetic number, because the mean of its divisors is an integer number (2040480).

Almost surely, 2^21369453 is an apocalyptic number.

21369453 is the 6537-th triangular number and also the 3269-th hexagonal number.

It is an amenable number.

21369453 is a deficient number, since it is larger than the sum of its proper divisors (11278227).

21369453 is a wasteful number, since it uses less digits than its factorization.

21369453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2656.

The product of its digits is 19440, while the sum is 33.

The square root of 21369453 is about 4622.7105684868. The cubic root of 21369453 is about 277.5009463485.

The spelling of 21369453 in words is "twenty-one million, three hundred sixty-nine thousand, four hundred fifty-three".