21454444 has 12 divisors (see below), whose sum is σ = 40958568. Its totient is φ = 9752000.

The previous prime is 21454441. The next prime is 21454483. The reversal of 21454444 is 44445412.

It is not an unprimeable number, because it can be changed into a prime (21454441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243757 + ... + 243844.

It is an arithmetic number, because the mean of its divisors is an integer number (3413214).

Almost surely, 2^21454444 is an apocalyptic number.

It is an amenable number.

21454444 is a deficient number, since it is larger than the sum of its proper divisors (19504124).

21454444 is a wasteful number, since it uses less digits than its factorization.

21454444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487616 (or 487614 counting only the distinct ones).

The product of its digits is 10240, while the sum is 28.

The square root of 21454444 is about 4631.8942129544. The cubic root of 21454444 is about 277.8683537276.

Adding to 21454444 its reverse (44445412), we get a palindrome (65899856).

The spelling of 21454444 in words is "twenty-one million, four hundred fifty-four thousand, four hundred forty-four".