21254872320 has 432 divisors, whose sum is σ = 82201863744. Its totient is φ = 5025792000.

The previous prime is 21254872313. The next prime is 21254872321. The reversal of 21254872320 is 2327845212.

21254872320 is a `hidden beast` number, since 2 + 1 + 254 + 87 + 2 + 320 = 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 (21254872321) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5193475 + ... + 5197565.

It is an arithmetic number, because the mean of its divisors is an integer number (190282092).

Almost surely, 2^21254872320 is an apocalyptic number.

21254872320 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 21254872320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41100931872).

21254872320 is an abundant number, since it is smaller than the sum of its proper divisors (60946991424).

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

21254872320 is a wasteful number, since it uses less digits than its factorization.

21254872320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4170 (or 4153 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The spelling of 21254872320 in words is "twenty-one billion, two hundred fifty-four million, eight hundred seventy-two thousand, three hundred twenty".