21342453 has 16 divisors (see below), whose sum is σ = 32678400. Its totient is φ = 12253680.

The previous prime is 21342449. The next prime is 21342457. The reversal of 21342453 is 35424312.

It is an interprime number because it is at equal distance from previous prime (21342449) and next prime (21342457).

It is not a de Polignac number, because 21342453 - 2² = 21342449 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21342457) 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, 16393 + ... + 17646.

It is an arithmetic number, because the mean of its divisors is an integer number (2042400).

Almost surely, 2^21342453 is an apocalyptic number.

It is an amenable number.

21342453 is a deficient number, since it is larger than the sum of its proper divisors (11335947).

21342453 is a wasteful number, since it uses less digits than its factorization.

21342453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34072.

The product of its digits is 2880, while the sum is 24.

The square root of 21342453 is about 4619.7892809088. The cubic root of 21342453 is about 277.3840242583.

Adding to 21342453 its reverse (35424312), we get a palindrome (56766765).

The spelling of 21342453 in words is "twenty-one million, three hundred forty-two thousand, four hundred fifty-three".