21743212 has 6 divisors (see below), whose sum is σ = 38050628. Its totient is φ = 10871604.

The previous prime is 21743207. The next prime is 21743213. The reversal of 21743212 is 21234712.

It is not an unprimeable number, because it can be changed into a prime (21743213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2717898 + ... + 2717905.

Almost surely, 2^21743212 is an apocalyptic number.

It is an amenable number.

21743212 is a deficient number, since it is larger than the sum of its proper divisors (16307416).

21743212 is a wasteful number, since it uses less digits than its factorization.

21743212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5435807 (or 5435805 counting only the distinct ones).

The product of its digits is 672, while the sum is 22.

The square root of 21743212 is about 4662.9617197657. The cubic root of 21743212 is about 279.1094666006.

Adding to 21743212 its reverse (21234712), we get a palindrome (42977924).

The spelling of 21743212 in words is "twenty-one million, seven hundred forty-three thousand, two hundred twelve".