21544091240 has 128 divisors (see below), whose sum is σ = 57959193600. Its totient is φ = 7052881920.

The previous prime is 21544091209. The next prime is 21544091299. The reversal of 21544091240 is 4219044512.

It is a junction number, because it is equal to n+sod(n) for n = 21544091197 and 21544091206.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 519596 + ... + 559524.

It is an arithmetic number, because the mean of its divisors is an integer number (452806200).

Almost surely, 2^21544091240 is an apocalyptic number.

21544091240 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 21544091240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28979596800).

21544091240 is an abundant number, since it is smaller than the sum of its proper divisors (36415102360).

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

21544091240 is a wasteful number, since it uses less digits than its factorization.

21544091240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40035 (or 40031 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The spelling of 21544091240 in words is "twenty-one billion, five hundred forty-four million, ninety-one thousand, two hundred forty".