21240430212 has 48 divisors (see below), whose sum is σ = 51374836800. Its totient is φ = 6822023040.

The previous prime is 21240430147. The next prime is 21240430223. The reversal of 21240430212 is 21203404212.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108714 + ... + 233022.

It is an arithmetic number, because the mean of its divisors is an integer number (1070309100).

Almost surely, 2^21240430212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21240430212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25687418400).

21240430212 is an abundant number, since it is smaller than the sum of its proper divisors (30134406588).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21240430212 is a wasteful number, since it uses less digits than its factorization.

21240430212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124836 (or 124834 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21240430212 its reverse (21203404212), we get a palindrome (42443834424).

The spelling of 21240430212 in words is "twenty-one billion, two hundred forty million, four hundred thirty thousand, two hundred twelve".