21214236 has 24 divisors (see below), whose sum is σ = 49624960. Its totient is φ = 7053552.

The previous prime is 21214231. The next prime is 21214247. The reversal of 21214236 is 63241212.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21214231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3255 + ... + 7281.

Almost surely, 2^21214236 is an apocalyptic number.

It is an amenable number.

21214236 is an abundant number, since it is smaller than the sum of its proper divisors (28410724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21214236 is a wasteful number, since it uses less digits than its factorization.

21214236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4473 (or 4471 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 21214236 is about 4605.8914446608. The cubic root of 21214236 is about 276.8274370823.

Adding to 21214236 its reverse (63241212), we get a palindrome (84455448).

The spelling of 21214236 in words is "twenty-one million, two hundred fourteen thousand, two hundred thirty-six".