21555022000 has 40 divisors (see below), whose sum is σ = 52120048032. Its totient is φ = 8622008000.

The previous prime is 21555021947. The next prime is 21555022057. The reversal of 21555022000 is 22055512.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5386756 + ... + 5390755.

Almost surely, 2^21555022000 is an apocalyptic number.

21555022000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21555022000 is an abundant number, since it is smaller than the sum of its proper divisors (30565026032).

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

21555022000 is a wasteful number, since it uses less digits than its factorization.

21555022000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10777534 (or 10777518 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 22.

Adding to 21555022000 its reverse (22055512), we get a palindrome (21577077512).

The spelling of 21555022000 in words is "twenty-one billion, five hundred fifty-five million, twenty-two thousand".