21555005500567 has 12 divisors (see below), whose sum is σ = 27077362282768. Its totient is φ = 16796108181600.

The previous prime is 21555005500559. The next prime is 21555005500583. The reversal of 21555005500567 is 76500550055512.

It is not a de Polignac number, because 21555005500567 - 2³ = 21555005500559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21555005500507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12724323534 + ... + 12724325227.

Almost surely, 2^{21555005500567} is an apocalyptic number.

21555005500567 is a deficient number, since it is larger than the sum of its proper divisors (5522356782201).

21555005500567 is a wasteful number, since it uses less digits than its factorization.

21555005500567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25448648790 (or 25448648779 counting only the distinct ones).

The product of its (nonzero) digits is 1312500, while the sum is 46.

Subtracting 21555005500567 from its reverse (76500550055512), we obtain a palindrome (54945544554945).

The spelling of 21555005500567 in words is "twenty-one trillion, five hundred fifty-five billion, five million, five hundred thousand, five hundred sixty-seven".