21442025515543 has 4 divisors (see below), whose sum is σ = 21483023652808. Its totient is φ = 21401027378280.

The previous prime is 21442025515523. The next prime is 21442025515601. The reversal of 21442025515543 is 34551552024412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21442025515543 - 2⁵ = 21442025515511 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21442025515543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442025515513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20499067848 + ... + 20499068893.

It is an arithmetic number, because the mean of its divisors is an integer number (5370755913202).

Almost surely, 2^{21442025515543} is an apocalyptic number.

21442025515543 is a deficient number, since it is larger than the sum of its proper divisors (40998137265).

21442025515543 is an equidigital number, since it uses as much as digits as its factorization.

21442025515543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40998137264.

The product of its (nonzero) digits is 960000, while the sum is 43.

Adding to 21442025515543 its reverse (34551552024412), we get a palindrome (55993577539955).

The spelling of 21442025515543 in words is "twenty-one trillion, four hundred forty-two billion, twenty-five million, five hundred fifteen thousand, five hundred forty-three".