21543552541 has 16 divisors (see below), whose sum is σ = 25227554688. Its totient is φ = 18011347200.

The previous prime is 21543552533. The next prime is 21543552571. The reversal of 21543552541 is 14525534512.

It is not a de Polignac number, because 21543552541 - 2³ = 21543552533 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21543552541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21543552521) 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, 2326681 + ... + 2335921.

It is an arithmetic number, because the mean of its divisors is an integer number (1576722168).

Almost surely, 2^21543552541 is an apocalyptic number.

It is an amenable number.

21543552541 is a deficient number, since it is larger than the sum of its proper divisors (3684002147).

21543552541 is an equidigital number, since it uses as much as digits as its factorization.

21543552541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17412.

The product of its digits is 120000, while the sum is 37.

The spelling of 21543552541 in words is "twenty-one billion, five hundred forty-three million, five hundred fifty-two thousand, five hundred forty-one".