21855628080 has 480 divisors, whose sum is σ = 87354408960. Its totient is φ = 4827064320.

The previous prime is 21855628079. The next prime is 21855628127. The reversal of 21855628080 is 8082655812.

21855628080 is a `hidden beast` number, since 2 + 1 + 8 + 5 + 562 + 8 + 0 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8132497 + ... + 8135183.

It is an arithmetic number, because the mean of its divisors is an integer number (181988352).

Almost surely, 2^21855628080 is an apocalyptic number.

21855628080 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 21855628080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43677204480).

21855628080 is an abundant number, since it is smaller than the sum of its proper divisors (65498780880).

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

21855628080 is a wasteful number, since it uses less digits than its factorization.

21855628080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2809 (or 2800 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 45.

The spelling of 21855628080 in words is "twenty-one billion, eight hundred fifty-five million, six hundred twenty-eight thousand, eighty".