21551084456 has 48 divisors (see below), whose sum is σ = 46346882400. Its totient is φ = 9370027040.

The previous prime is 21551084449. The next prime is 21551084483. The reversal of 21551084456 is 65448015512.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 461726 + ... + 506253.

It is an arithmetic number, because the mean of its divisors is an integer number (965560050).

Almost surely, 2^21551084456 is an apocalyptic number.

It is an amenable number.

21551084456 is an abundant number, since it is smaller than the sum of its proper divisors (24795797944).

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

21551084456 is a wasteful number, since it uses less digits than its factorization.

21551084456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 968030 (or 968015 counting only the distinct ones).

The product of its (nonzero) digits is 192000, while the sum is 41.

Adding to 21551084456 its reverse (65448015512), we get a palindrome (86999099968).

The spelling of 21551084456 in words is "twenty-one billion, five hundred fifty-one million, eighty-four thousand, four hundred fifty-six".