21251040000 has 180 divisors, whose sum is σ = 70677419736. Its totient is φ = 5666816000.

The previous prime is 21251039993. The next prime is 21251040017. The reversal of 21251040000 is 4015212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 457864 + ... + 502136.

Almost surely, 2^21251040000 is an apocalyptic number.

21251040000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21251040000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35338709868).

21251040000 is an abundant number, since it is smaller than the sum of its proper divisors (49426379736).

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

21251040000 is an frugal number, since it uses more digits than its factorization.

21251040000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44312 (or 44283 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

Adding to 21251040000 its reverse (4015212), we get a palindrome (21255055212).

The spelling of 21251040000 in words is "twenty-one billion, two hundred fifty-one million, forty thousand".