21402212 has 24 divisors (see below), whose sum is σ = 40943616. Its totient is φ = 9728928.

The previous prime is 21402209. The next prime is 21402217. The reversal of 21402212 is 21220412.

It is not an unprimeable number, because it can be changed into a prime (21402217) 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, 413 + ... + 6555.

It is an arithmetic number, because the mean of its divisors is an integer number (1705984).

Almost surely, 2^21402212 is an apocalyptic number.

It is an amenable number.

21402212 is a deficient number, since it is larger than the sum of its proper divisors (19541404).

21402212 is a wasteful number, since it uses less digits than its factorization.

21402212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6227 (or 6225 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 21402212 is about 4626.2524790590. The cubic root of 21402212 is about 277.6426753262.

Adding to 21402212 its reverse (21220412), we get a palindrome (42622624).

The spelling of 21402212 in words is "twenty-one million, four hundred two thousand, two hundred twelve".