21320311100 has 72 divisors (see below), whose sum is σ = 50595459600. Its totient is φ = 7733721600.

The previous prime is 21320311093. The next prime is 21320311123. The reversal of 21320311100 is 111302312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 426206 + ... + 473594.

Almost surely, 2^21320311100 is an apocalyptic number.

21320311100 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 21320311100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25297729800).

21320311100 is an abundant number, since it is smaller than the sum of its proper divisors (29275148500).

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

21320311100 is a wasteful number, since it uses less digits than its factorization.

21320311100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47823 (or 47816 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21320311100 its reverse (111302312), we get a palindrome (21431613412).

The spelling of 21320311100 in words is "twenty-one billion, three hundred twenty million, three hundred eleven thousand, one hundred".