21544454 has 4 divisors (see below), whose sum is σ = 32316684. Its totient is φ = 10772226.

The previous prime is 21544451. The next prime is 21544463. The reversal of 21544454 is 45444512.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21544451) 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 as a sum of consecutive naturals, namely, 5386112 + ... + 5386115.

It is an arithmetic number, because the mean of its divisors is an integer number (8079171).

Almost surely, 2^21544454 is an apocalyptic number.

21544454 is a deficient number, since it is larger than the sum of its proper divisors (10772230).

21544454 is a wasteful number, since it uses less digits than its factorization.

21544454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10772229.

The product of its digits is 12800, while the sum is 29.

The square root of 21544454 is about 4641.6003705619. The cubic root of 21544454 is about 278.2564013018.

Adding to 21544454 its reverse (45444512), we get a palindrome (66988966).

The spelling of 21544454 in words is "twenty-one million, five hundred forty-four thousand, four hundred fifty-four".