21144453 has 8 divisors (see below), whose sum is σ = 30755616. Its totient is φ = 12814800.

The previous prime is 21144437. The next prime is 21144467. The reversal of 21144453 is 35444112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21144453 - 2⁴ = 21144437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320338 + ... + 320403.

It is an arithmetic number, because the mean of its divisors is an integer number (3844452).

Almost surely, 2^21144453 is an apocalyptic number.

It is an amenable number.

21144453 is a deficient number, since it is larger than the sum of its proper divisors (9611163).

21144453 is a wasteful number, since it uses less digits than its factorization.

21144453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640755.

The product of its digits is 1920, while the sum is 24.

The square root of 21144453 is about 4598.3097981758. The cubic root of 21144453 is about 276.5235677138.

Adding to 21144453 its reverse (35444112), we get a palindrome (56588565).

The spelling of 21144453 in words is "twenty-one million, one hundred forty-four thousand, four hundred fifty-three".