21442544 has 10 divisors (see below), whose sum is σ = 41544960. Its totient is φ = 10721264.

The previous prime is 21442543. The next prime is 21442591. The reversal of 21442544 is 44524412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 670064 + ... + 670095.

It is an arithmetic number, because the mean of its divisors is an integer number (4154496).

Almost surely, 2^21442544 is an apocalyptic number.

It is an amenable number.

21442544 is a deficient number, since it is larger than the sum of its proper divisors (20102416).

21442544 is a wasteful number, since it uses less digits than its factorization.

21442544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1340167 (or 1340161 counting only the distinct ones).

The product of its digits is 5120, while the sum is 26.

The square root of 21442544 is about 4630.6094631269. The cubic root of 21442544 is about 277.8169697353.

Adding to 21442544 its reverse (44524412), we get a palindrome (65966956).

The spelling of 21442544 in words is "twenty-one million, four hundred forty-two thousand, five hundred forty-four".