21563514464 has 24 divisors (see below), whose sum is σ = 43172718120. Its totient is φ = 10599014656.

The previous prime is 21563514463. The next prime is 21563514473. The reversal of 21563514464 is 46441536512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21563514463) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 5708789 + ... + 5712564.

It is an arithmetic number, because the mean of its divisors is an integer number (1798863255).

Almost surely, 2^21563514464 is an apocalyptic number.

It is an amenable number.

21563514464 is an abundant number, since it is smaller than the sum of its proper divisors (21609203656).

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

21563514464 is a wasteful number, since it uses less digits than its factorization.

21563514464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11421422 (or 11421414 counting only the distinct ones).

The product of its digits is 345600, while the sum is 41.

The spelling of 21563514464 in words is "twenty-one billion, five hundred sixty-three million, five hundred fourteen thousand, four hundred sixty-four".