21241145500 has 96 divisors (see below), whose sum is σ = 47273099328. Its totient is φ = 8335584000.

The previous prime is 21241145491. The next prime is 21241145501. The reversal of 21241145500 is 554114212.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21241145501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17170882 + ... + 17172118.

It is an arithmetic number, because the mean of its divisors is an integer number (492428118).

Almost surely, 2^21241145500 is an apocalyptic number.

21241145500 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 21241145500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23636549664).

21241145500 is an abundant number, since it is smaller than the sum of its proper divisors (26031953828).

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

21241145500 is a wasteful number, since it uses less digits than its factorization.

21241145500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1880 (or 1868 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 21241145500 its reverse (554114212), we get a palindrome (21795259712).

The spelling of 21241145500 in words is "twenty-one billion, two hundred forty-one million, one hundred forty-five thousand, five hundred".