21011025152 has 144 divisors (see below), whose sum is σ = 48309588432. Its totient is φ = 9034137600.

The previous prime is 21011025137. The next prime is 21011025187. The reversal of 21011025152 is 25152011012.

It can be written as a sum of positive squares in 8 ways, for example, as 3264522496 + 17746502656 = 57136^2 + 133216^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5712338 + ... + 5716014.

It is an arithmetic number, because the mean of its divisors is an integer number (335483253).

Almost surely, 2^21011025152 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 21011025152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24154794216).

21011025152 is an abundant number, since it is smaller than the sum of its proper divisors (27298563280).

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

21011025152 is a wasteful number, since it uses less digits than its factorization.

21011025152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3824 (or 3810 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 20.

Adding to 21011025152 its reverse (25152011012), we get a palindrome (46163036164).

The spelling of 21011025152 in words is "twenty-one billion, eleven million, twenty-five thousand, one hundred fifty-two".