21231243372 has 24 divisors (see below), whose sum is σ = 49592919600. Its totient is φ = 7069459456.

The previous prime is 21231243349. The next prime is 21231243403. The reversal of 21231243372 is 27334213212.

It is an unprimeable number.

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, 941097 + ... + 963392.

It is an arithmetic number, because the mean of its divisors is an integer number (2066371650).

Almost surely, 2^21231243372 is an apocalyptic number.

It is an amenable number.

21231243372 is an abundant number, since it is smaller than the sum of its proper divisors (28361676228).

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

21231243372 is a wasteful number, since it uses less digits than its factorization.

21231243372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1905425 (or 1905423 counting only the distinct ones).

The product of its digits is 12096, while the sum is 30.

Adding to 21231243372 its reverse (27334213212), we get a palindrome (48565456584).

The spelling of 21231243372 in words is "twenty-one billion, two hundred thirty-one million, two hundred forty-three thousand, three hundred seventy-two".