21164035744 has 48 divisors (see below), whose sum is σ = 43211727720. Its totient is φ = 10191462400.

The previous prime is 21164035733. The next prime is 21164035747. The reversal of 21164035744 is 44753046112.

It can be written as a sum of positive squares in 4 ways, for example, as 19137955600 + 2026080144 = 138340^2 + 45012^2 .

It is not an unprimeable number, because it can be changed into a prime (21164035747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 343692 + ... + 400564.

Almost surely, 2^21164035744 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 21164035744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21605863860).

21164035744 is an abundant number, since it is smaller than the sum of its proper divisors (22047691976).

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

21164035744 is a wasteful number, since it uses less digits than its factorization.

21164035744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57313 (or 57305 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 37.

The spelling of 21164035744 in words is "twenty-one billion, one hundred sixty-four million, thirty-five thousand, seven hundred forty-four".