21555543041 has 4 divisors (see below), whose sum is σ = 21877267632. Its totient is φ = 21233818452.

The previous prime is 21555543001. The next prime is 21555543047. The reversal of 21555543041 is 14034555512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21555543041 - 2³⁴ = 4375673857 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21555542992 and 21555543010.

It is not an unprimeable number, because it can be changed into a prime (21555543047) 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, 160862195 + ... + 160862328.

It is an arithmetic number, because the mean of its divisors is an integer number (5469316908).

Almost surely, 2^21555543041 is an apocalyptic number.

It is an amenable number.

21555543041 is a deficient number, since it is larger than the sum of its proper divisors (321724591).

21555543041 is an equidigital number, since it uses as much as digits as its factorization.

21555543041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321724590.

The product of its (nonzero) digits is 60000, while the sum is 35.

The spelling of 21555543041 in words is "twenty-one billion, five hundred fifty-five million, five hundred forty-three thousand, forty-one".