21230442012 has 48 divisors (see below), whose sum is σ = 53706391200. Its totient is φ = 6488594688.

The previous prime is 21230442011. The next prime is 21230442017. The reversal of 21230442012 is 21024403212.

It is a self number, because there is not a number n which added to its sum of digits gives 21230442012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230442011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 433443 + ... + 479930.

It is an arithmetic number, because the mean of its divisors is an integer number (1118883150).

Almost surely, 2^21230442012 is an apocalyptic number.

It is an amenable number.

21230442012 is an abundant number, since it is smaller than the sum of its proper divisors (32475949188).

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

21230442012 is a wasteful number, since it uses less digits than its factorization.

21230442012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913542 (or 913540 counting only the distinct ones).

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

Adding to 21230442012 its reverse (21024403212), we get a palindrome (42254845224).

The spelling of 21230442012 in words is "twenty-one billion, two hundred thirty million, four hundred forty-two thousand, twelve".