21335013444 has 12 divisors (see below), whose sum is σ = 49781698064. Its totient is φ = 7111671144.

The previous prime is 21335013433. The next prime is 21335013499. The reversal of 21335013444 is 44431053312.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21335013444² (a number of 21 digits) contains 22 as substring.

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, 888958882 + ... + 888958905.

Almost surely, 2^21335013444 is an apocalyptic number.

It is an amenable number.

21335013444 is an abundant number, since it is smaller than the sum of its proper divisors (28446684620).

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

21335013444 is a wasteful number, since it uses less digits than its factorization.

21335013444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1777917794 (or 1777917792 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 30.

Adding to 21335013444 its reverse (44431053312), we get a palindrome (65766066756).

The spelling of 21335013444 in words is "twenty-one billion, three hundred thirty-five million, thirteen thousand, four hundred forty-four".