21331212840 has 256 divisors, whose sum is σ = 83884032000. Its totient is φ = 4718373120.

The previous prime is 21331212839. The next prime is 21331212853. The reversal of 21331212840 is 4821213312.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 188851 + ... + 279869.

It is an arithmetic number, because the mean of its divisors is an integer number (327672000).

Almost surely, 2^21331212840 is an apocalyptic number.

21331212840 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 21331212840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41942016000).

21331212840 is an abundant number, since it is smaller than the sum of its proper divisors (62552819160).

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

21331212840 is a wasteful number, since it uses less digits than its factorization.

21331212840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91077 (or 91067 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The spelling of 21331212840 in words is "twenty-one billion, three hundred thirty-one million, two hundred twelve thousand, eight hundred forty".