21442538880 has 384 divisors, whose sum is σ = 85122835200. Its totient is φ = 4872130560.

The previous prime is 21442538869. The next prime is 21442538881. The reversal of 21442538880 is 8883524412.

21442538880 is a `hidden beast` number, since 2 + 1 + 442 + 53 + 88 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442538881) 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, 7215795 + ... + 7218765.

It is an arithmetic number, because the mean of its divisors is an integer number (221674050).

Almost surely, 2^21442538880 is an apocalyptic number.

21442538880 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 21442538880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42561417600).

21442538880 is an abundant number, since it is smaller than the sum of its proper divisors (63680296320).

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

21442538880 is a wasteful number, since it uses less digits than its factorization.

21442538880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3182 (or 3167 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The spelling of 21442538880 in words is "twenty-one billion, four hundred forty-two million, five hundred thirty-eight thousand, eight hundred eighty".