21214436 has 24 divisors (see below), whose sum is σ = 39513600. Its totient is φ = 9931392.

The previous prime is 21214433. The next prime is 21214451. The reversal of 21214436 is 63441212.

It is not an unprimeable number, because it can be changed into a prime (21214433) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14465 + ... + 15863.

It is an arithmetic number, because the mean of its divisors is an integer number (1646400).

Almost surely, 2^21214436 is an apocalyptic number.

It is an amenable number.

21214436 is a deficient number, since it is larger than the sum of its proper divisors (18299164).

21214436 is a wasteful number, since it uses less digits than its factorization.

21214436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1643 (or 1641 counting only the distinct ones).

The product of its digits is 1152, while the sum is 23.

The square root of 21214436 is about 4605.9131559334. The cubic root of 21214436 is about 276.8283070219.

Adding to 21214436 its reverse (63441212), we get a palindrome (84655648).

The spelling of 21214436 in words is "twenty-one million, two hundred fourteen thousand, four hundred thirty-six".