21204131144 has 96 divisors (see below), whose sum is σ = 49932936000. Its totient is φ = 8257815552.

The previous prime is 21204131131. The next prime is 21204131149. The reversal of 21204131144 is 44113140212.

It is not an unprimeable number, because it can be changed into a prime (21204131149) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 446747 + ... + 491925.

It is an arithmetic number, because the mean of its divisors is an integer number (520134750).

Almost surely, 2^21204131144 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 21204131144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24966468000).

21204131144 is an abundant number, since it is smaller than the sum of its proper divisors (28728804856).

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

21204131144 is a wasteful number, since it uses less digits than its factorization.

21204131144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45255 (or 45234 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 21204131144 its reverse (44113140212), we get a palindrome (65317271356).

The spelling of 21204131144 in words is "twenty-one billion, two hundred four million, one hundred thirty-one thousand, one hundred forty-four".