21331113020 has 96 divisors (see below), whose sum is σ = 53124857856. Its totient is φ = 7040275200.

The previous prime is 21331113019. The next prime is 21331113049. The reversal of 21331113020 is 2031113312.

It is a self number, because there is not a number n which added to its sum of digits gives 21331113020.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 816074 + ... + 841806.

It is an arithmetic number, because the mean of its divisors is an integer number (553383936).

Almost surely, 2^21331113020 is an apocalyptic number.

21331113020 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 21331113020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26562428928).

21331113020 is an abundant number, since it is smaller than the sum of its proper divisors (31793744836).

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

21331113020 is a wasteful number, since it uses less digits than its factorization.

21331113020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25971 (or 25969 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21331113020 its reverse (2031113312), we get a palindrome (23362226332).

The spelling of 21331113020 in words is "twenty-one billion, three hundred thirty-one million, one hundred thirteen thousand, twenty".