21231142442 has 16 divisors (see below), whose sum is σ = 32020310400. Its totient is φ = 10557751248.

The previous prime is 21231142409. The next prime is 21231142447. The reversal of 21231142442 is 24424113212.

It is a super-2 number, since 2×21231142442² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21231142447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1055483 + ... + 1075409.

It is an arithmetic number, because the mean of its divisors is an integer number (2001269400).

Almost surely, 2^21231142442 is an apocalyptic number.

21231142442 is a deficient number, since it is larger than the sum of its proper divisors (10789167958).

21231142442 is a wasteful number, since it uses less digits than its factorization.

21231142442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22805.

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

Adding to 21231142442 its reverse (24424113212), we get a palindrome (45655255654).

The spelling of 21231142442 in words is "twenty-one billion, two hundred thirty-one million, one hundred forty-two thousand, four hundred forty-two".