21555534222 has 24 divisors (see below), whose sum is σ = 47965919976. Its totient is φ = 6990983856.

The previous prime is 21555534179. The next prime is 21555534227. The reversal of 21555534222 is 22243555512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21555534227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16182168 + ... + 16183499.

It is an arithmetic number, because the mean of its divisors is an integer number (1998579999).

Almost surely, 2^21555534222 is an apocalyptic number.

21555534222 is an abundant number, since it is smaller than the sum of its proper divisors (26410385754).

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

21555534222 is a wasteful number, since it uses less digits than its factorization.

21555534222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32365712 (or 32365709 counting only the distinct ones).

The product of its digits is 120000, while the sum is 36.

The spelling of 21555534222 in words is "twenty-one billion, five hundred fifty-five million, five hundred thirty-four thousand, two hundred twenty-two".