21550055320 has 16 divisors (see below), whose sum is σ = 48487624560. Its totient is φ = 8620022112.

The previous prime is 21550055281. The next prime is 21550055327. The reversal of 21550055320 is 2355005512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21550055327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 269375652 + ... + 269375731.

It is an arithmetic number, because the mean of its divisors is an integer number (3030476535).

Almost surely, 2^21550055320 is an apocalyptic number.

21550055320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21550055320 is an abundant number, since it is smaller than the sum of its proper divisors (26937569240).

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

21550055320 is a wasteful number, since it uses less digits than its factorization.

21550055320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538751394 (or 538751390 counting only the distinct ones).

The product of its (nonzero) digits is 7500, while the sum is 28.

The spelling of 21550055320 in words is "twenty-one billion, five hundred fifty million, fifty-five thousand, three hundred twenty".