21443379552 has 144 divisors (see below), whose sum is σ = 69749971200. Its totient is φ = 6121495296.

The previous prime is 21443379533. The next prime is 21443379557. The reversal of 21443379552 is 25597334412.

It is a happy number.

21443379552 is a `hidden beast` number, since 21 + 4 + 4 + 3 + 3 + 79 + 552 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×21443379552² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21443379498 and 21443379507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21443379557) 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, 2816583 + ... + 2824185.

It is an arithmetic number, because the mean of its divisors is an integer number (484374800).

Almost surely, 2^21443379552 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 21443379552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34874985600).

21443379552 is an abundant number, since it is smaller than the sum of its proper divisors (48306591648).

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

21443379552 is a wasteful number, since it uses less digits than its factorization.

21443379552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9025 (or 9014 counting only the distinct ones).

The product of its digits is 907200, while the sum is 45.

The spelling of 21443379552 in words is "twenty-one billion, four hundred forty-three million, three hundred seventy-nine thousand, five hundred fifty-two".