21234212 has 6 divisors (see below), whose sum is σ = 37159878. Its totient is φ = 10617104.

The previous prime is 21234211. The next prime is 21234281. The reversal of 21234212 is 21243212.

It can be written as a sum of positive squares in only one way, i.e., 19855936 + 1378276 = 4456^2 + 1174^2 .

It is not an unprimeable number, because it can be changed into a prime (21234211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2654273 + ... + 2654280.

It is an arithmetic number, because the mean of its divisors is an integer number (6193313).

Almost surely, 2^21234212 is an apocalyptic number.

It is an amenable number.

21234212 is a deficient number, since it is larger than the sum of its proper divisors (15925666).

21234212 is a wasteful number, since it uses less digits than its factorization.

21234212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5308557 (or 5308555 counting only the distinct ones).

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

The square root of 21234212 is about 4608.0594614219. The cubic root of 21234212 is about 276.9142996664.

Adding to 21234212 its reverse (21243212), we get a palindrome (42477424).

The spelling of 21234212 in words is "twenty-one million, two hundred thirty-four thousand, two hundred twelve".