21259055431920 has 320 divisors, whose sum is σ = 67686017817600. Its totient is φ = 5516450734080.

The previous prime is 21259055431883. The next prime is 21259055431963. The reversal of 21259055431920 is 2913455095212.

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 21259055431920.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10477601466 + ... + 10477603494.

It is an arithmetic number, because the mean of its divisors is an integer number (211518805680).

Almost surely, 2^{21259055431920} is an apocalyptic number.

21259055431920 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 21259055431920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33843008908800).

21259055431920 is an abundant number, since it is smaller than the sum of its proper divisors (46426962385680).

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

21259055431920 is a wasteful number, since it uses less digits than its factorization.

21259055431920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4328 (or 4322 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 48.

The spelling of 21259055431920 in words is "twenty-one trillion, two hundred fifty-nine billion, fifty-five million, four hundred thirty-one thousand, nine hundred twenty".