21444286 has 4 divisors (see below), whose sum is σ = 32166432. Its totient is φ = 10722142.

The previous prime is 21444263. The next prime is 21444287. The reversal of 21444286 is 68244412.

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 (21444287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5361070 + ... + 5361073.

It is an arithmetic number, because the mean of its divisors is an integer number (8041608).

Almost surely, 2^21444286 is an apocalyptic number.

21444286 is a deficient number, since it is larger than the sum of its proper divisors (10722146).

21444286 is a wasteful number, since it uses less digits than its factorization.

21444286 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10722145.

The product of its digits is 12288, while the sum is 31.

The square root of 21444286 is about 4630.7975554973. The cubic root of 21444286 is about 277.8244928485.

Adding to 21444286 its reverse (68244412), we get a palindrome (89688698).

The spelling of 21444286 in words is "twenty-one million, four hundred forty-four thousand, two hundred eighty-six".