21002845448 has 40 divisors (see below), whose sum is σ = 42662379030. Its totient is φ = 9693515520.

The previous prime is 21002845411. The next prime is 21002845453. The reversal of 21002845448 is 84454820012.

It can be written as a sum of positive squares in 5 ways, for example, as 6065605924 + 14937239524 = 77882^2 + 122218^2 .

It is a super-2 number, since 2×21002845448² (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 9 ways as a sum of consecutive naturals, for example, 182528 + ... + 274448.

Almost surely, 2^21002845448 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 21002845448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21331189515).

21002845448 is an abundant number, since it is smaller than the sum of its proper divisors (21659533582).

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

21002845448 is an frugal number, since it uses more digits than its factorization.

21002845448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91979 (or 91936 counting only the distinct ones).

The product of its (nonzero) digits is 81920, while the sum is 38.

The spelling of 21002845448 in words is "twenty-one billion, two million, eight hundred forty-five thousand, four hundred forty-eight".