21240305324212 has 24 divisors (see below), whose sum is σ = 40032769830536. Its totient is φ = 9802492051968.

The previous prime is 21240305324207. The next prime is 21240305324243. The reversal of 21240305324212 is 21242350304212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 112732091536 + 21127573232676 = 335756^2 + 4596474^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14411193 + ... + 15816544.

Almost surely, 2^{21240305324212} is an apocalyptic number.

It is an amenable number.

21240305324212 is a deficient number, since it is larger than the sum of its proper divisors (18792464506324).

21240305324212 is a wasteful number, since it uses less digits than its factorization.

21240305324212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30241267 (or 30241265 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 31.

Adding to 21240305324212 its reverse (21242350304212), we get a palindrome (42482655628424).

The spelling of 21240305324212 in words is "twenty-one trillion, two hundred forty billion, three hundred five million, three hundred twenty-four thousand, two hundred twelve".