21424431212 has 12 divisors (see below), whose sum is σ = 37529483376. Its totient is φ = 10701721680.

The previous prime is 21424431211. The next prime is 21424431233. The reversal of 21424431212 is 21213442412.

It is not an unprimeable number, because it can be changed into a prime (21424431211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2618888 + ... + 2627055.

It is an arithmetic number, because the mean of its divisors is an integer number (3127456948).

Almost surely, 2^21424431212 is an apocalyptic number.

It is an amenable number.

21424431212 is a deficient number, since it is larger than the sum of its proper divisors (16105052164).

21424431212 is a wasteful number, since it uses less digits than its factorization.

21424431212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5246968 (or 5246966 counting only the distinct ones).

The product of its digits is 3072, while the sum is 26.

Adding to 21424431212 its reverse (21213442412), we get a palindrome (42637873624).

The spelling of 21424431212 in words is "twenty-one billion, four hundred twenty-four million, four hundred thirty-one thousand, two hundred twelve".