21250311100 has 144 divisors (see below), whose sum is σ = 49677945408. Its totient is φ = 7861800960.

The previous prime is 21250311011. The next prime is 21250311197. The reversal of 21250311100 is 111305212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 27490314 + ... + 27491086.

It is an arithmetic number, because the mean of its divisors is an integer number (344985732).

Almost surely, 2^21250311100 is an apocalyptic number.

21250311100 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 21250311100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24838972704).

21250311100 is an abundant number, since it is smaller than the sum of its proper divisors (28427634308).

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

21250311100 is a wasteful number, since it uses less digits than its factorization.

21250311100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1064 (or 1057 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 16.

Adding to 21250311100 its reverse (111305212), we get a palindrome (21361616312).

The spelling of 21250311100 in words is "twenty-one billion, two hundred fifty million, three hundred eleven thousand, one hundred".