21272212 has 12 divisors (see below), whose sum is σ = 40090036. Its totient is φ = 9817920.

The previous prime is 21272189. The next prime is 21272213. The reversal of 21272212 is 21227212.

It can be written as a sum of positive squares in 2 ways, for example, as 4511376 + 16760836 = 2124^2 + 4094^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21272212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 204489 + ... + 204592.

Almost surely, 2^21272212 is an apocalyptic number.

It is an amenable number.

21272212 is a deficient number, since it is larger than the sum of its proper divisors (18817824).

21272212 is a wasteful number, since it uses less digits than its factorization.

21272212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409098 (or 409096 counting only the distinct ones).

The product of its digits is 224, while the sum is 19.

The square root of 21272212 is about 4612.1808290656. The cubic root of 21272212 is about 277.0793865959.

Adding to 21272212 its reverse (21227212), we get a palindrome (42499424).

The spelling of 21272212 in words is "twenty-one million, two hundred seventy-two thousand, two hundred twelve".