21323193840 has 640 divisors, whose sum is σ = 88194355200. Its totient is φ = 4678041600.

The previous prime is 21323193811. The next prime is 21323193907. The reversal of 21323193840 is 4839132312.

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

It is a junction number, because it is equal to n+sod(n) for n = 21323193795 and 21323193804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 9068665 + ... + 9071015.

It is an arithmetic number, because the mean of its divisors is an integer number (137803680).

Almost surely, 2^21323193840 is an apocalyptic number.

21323193840 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 21323193840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44097177600).

21323193840 is an abundant number, since it is smaller than the sum of its proper divisors (66871161360).

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

21323193840 is a wasteful number, since it uses less digits than its factorization.

21323193840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2422 (or 2410 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The spelling of 21323193840 in words is "twenty-one billion, three hundred twenty-three million, one hundred ninety-three thousand, eight hundred forty".