21541112544 has 96 divisors (see below), whose sum is σ = 64698794496. Its totient is φ = 6147417600.

The previous prime is 21541112543. The next prime is 21541112557. The reversal of 21541112544 is 44521114512.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541112543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 571069 + ... + 607619.

It is an arithmetic number, because the mean of its divisors is an integer number (673945776).

Almost surely, 2^21541112544 is an apocalyptic number.

21541112544 is a gapful number since it is divisible by the number (24) 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 21541112544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32349397248).

21541112544 is an abundant number, since it is smaller than the sum of its proper divisors (43157681952).

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

21541112544 is a wasteful number, since it uses less digits than its factorization.

21541112544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37448 (or 37440 counting only the distinct ones).

The product of its digits is 6400, while the sum is 30.

The spelling of 21541112544 in words is "twenty-one billion, five hundred forty-one million, one hundred twelve thousand, five hundred forty-four".