21323709603840 has 448 divisors, whose sum is σ = 78120846088704. Its totient is φ = 4865131020288.

The previous prime is 21323709603811. The next prime is 21323709603841. The reversal of 21323709603840 is 4830690732312.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21323709603840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323709603841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 479086867 + ... + 479131373.

Almost surely, 2^{21323709603840} is an apocalyptic number.

21323709603840 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 21323709603840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39060423044352).

21323709603840 is an abundant number, since it is smaller than the sum of its proper divisors (56797136484864).

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

21323709603840 is an equidigital number, since it uses as much as digits as its factorization.

21323709603840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45105 (or 45081 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 48.

The spelling of 21323709603840 in words is "twenty-one trillion, three hundred twenty-three billion, seven hundred nine million, six hundred three thousand, eight hundred forty".