21280512704 has 224 divisors, whose sum is σ = 49118641920. Its totient is φ = 9060249600.

The previous prime is 21280512703. The next prime is 21280512767. The reversal of 21280512704 is 40721508212.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is not an unprimeable number, because it can be changed into a prime (21280512703) 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 31 ways as a sum of consecutive naturals, for example, 93746639 + ... + 93746865.

Almost surely, 2^21280512704 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21280512704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24559320960).

21280512704 is an abundant number, since it is smaller than the sum of its proper divisors (27838129216).

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

21280512704 is a wasteful number, since it uses less digits than its factorization.

21280512704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 32.

The spelling of 21280512704 in words is "twenty-one billion, two hundred eighty million, five hundred twelve thousand, seven hundred four".