21236013444 has 24 divisors (see below), whose sum is σ = 49553259840. Its totient is φ = 7078305184.

The previous prime is 21236013443. The next prime is 21236013467. The reversal of 21236013444 is 44431063212.

It is a super-2 number, since 2×21236013444² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21236013443) 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, 301417 + ... + 365135.

It is an arithmetic number, because the mean of its divisors is an integer number (2064719160).

Almost surely, 2^21236013444 is an apocalyptic number.

It is an amenable number.

21236013444 is an abundant number, since it is smaller than the sum of its proper divisors (28317246396).

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

21236013444 is a wasteful number, since it uses less digits than its factorization.

21236013444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91499 (or 91497 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

Adding to 21236013444 its reverse (44431063212), we get a palindrome (65667076656).

The spelling of 21236013444 in words is "twenty-one billion, two hundred thirty-six million, thirteen thousand, four hundred forty-four".