21331312884 has 216 divisors, whose sum is σ = 65356200000. Its totient is φ = 5844061440.

The previous prime is 21331312883. The next prime is 21331312903. The reversal of 21331312884 is 48821313312.

21331312884 is a `hidden beast` number, since 2 + 1 + 331 + 312 + 8 + 8 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331312883) by changing a digit.

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 71 ways as a sum of consecutive naturals, for example, 4264617 + ... + 4269615.

It is an arithmetic number, because the mean of its divisors is an integer number (302575000).

Almost surely, 2^21331312884 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21331312884, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32678100000).

21331312884 is an abundant number, since it is smaller than the sum of its proper divisors (44024887116).

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

21331312884 is a wasteful number, since it uses less digits than its factorization.

21331312884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5123 (or 5111 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The spelling of 21331312884 in words is "twenty-one billion, three hundred thirty-one million, three hundred twelve thousand, eight hundred eighty-four".