21145234044 has 96 divisors (see below), whose sum is σ = 57062541312. Its totient is φ = 6033312000.

The previous prime is 21145234039. The next prime is 21145234051. The reversal of 21145234044 is 44043254112.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 81574 + ... + 221234.

It is an arithmetic number, because the mean of its divisors is an integer number (594401472).

Almost surely, 2^21145234044 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 21145234044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28531270656).

21145234044 is an abundant number, since it is smaller than the sum of its proper divisors (35917307268).

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

21145234044 is a wasteful number, since it uses less digits than its factorization.

21145234044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139747 (or 139745 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 30.

Adding to 21145234044 its reverse (44043254112), we get a palindrome (65188488156).

The spelling of 21145234044 in words is "twenty-one billion, one hundred forty-five million, two hundred thirty-four thousand, forty-four".