21536863512 has 64 divisors (see below), whose sum is σ = 54103173600. Its totient is φ = 7144243200.

The previous prime is 21536863507. The next prime is 21536863519.

21536863512 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21536863519) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4483512 + ... + 4488312.

Almost surely, 2^21536863512 is an apocalyptic number.

It is an amenable number.

21536863512 is an abundant number, since it is smaller than the sum of its proper divisors (32566310088).

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

21536863512 is a wasteful number, since it uses less digits than its factorization.

21536863512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5676 (or 5672 counting only the distinct ones).

The product of its digits is 259200, while the sum is 42.

The spelling of 21536863512 in words is "twenty-one billion, five hundred thirty-six million, eight hundred sixty-three thousand, five hundred twelve".