21313332544 has 28 divisors (see below), whose sum is σ = 48335594464. Its totient is φ = 9134285184.

The previous prime is 21313332533. The next prime is 21313332569. The reversal of 21313332544 is 44523331312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (28).

It is a super-2 number, since 2×21313332544² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23786754 + ... + 23787649.

Almost surely, 2^21313332544 is an apocalyptic number.

It is an amenable number.

21313332544 is an abundant number, since it is smaller than the sum of its proper divisors (27022261920).

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

21313332544 is an equidigital number, since it uses as much as digits as its factorization.

21313332544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47574422 (or 47574412 counting only the distinct ones).

The product of its digits is 25920, while the sum is 31.

Adding to 21313332544 its reverse (44523331312), we get a palindrome (65836663856).

The spelling of 21313332544 in words is "twenty-one billion, three hundred thirteen million, three hundred thirty-two thousand, five hundred forty-four".