21432212 has 6 divisors (see below), whose sum is σ = 37506378. Its totient is φ = 10716104.

The previous prime is 21432211. The next prime is 21432233. The reversal of 21432212 is 21223412.

It can be written as a sum of positive squares in only one way, i.e., 19483396 + 1948816 = 4414^2 + 1396^2 .

It is a super-2 number, since 2×21432212² = 918679422425888, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432211) 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 as a sum of consecutive naturals, namely, 2679023 + ... + 2679030.

It is an arithmetic number, because the mean of its divisors is an integer number (6251063).

Almost surely, 2^21432212 is an apocalyptic number.

It is an amenable number.

21432212 is a deficient number, since it is larger than the sum of its proper divisors (16074166).

21432212 is a wasteful number, since it uses less digits than its factorization.

21432212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5358057 (or 5358055 counting only the distinct ones).

The product of its digits is 192, while the sum is 17.

The square root of 21432212 is about 4629.4937088196. The cubic root of 21432212 is about 277.7723409188.

Adding to 21432212 its reverse (21223412), we get a palindrome (42655624).

The spelling of 21432212 in words is "twenty-one million, four hundred thirty-two thousand, two hundred twelve".