21965656912 has 20 divisors (see below), whose sum is σ = 42639850240. Its totient is φ = 10961824608.

The previous prime is 21965656907. The next prime is 21965656913.

21965656912 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 21965656912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21965656913) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1304112 + ... + 1320847.

It is an arithmetic number, because the mean of its divisors is an integer number (2131992512).

Almost surely, 2^21965656912 is an apocalyptic number.

It is an amenable number.

21965656912 is a deficient number, since it is larger than the sum of its proper divisors (20674193328).

21965656912 is a wasteful number, since it uses less digits than its factorization.

21965656912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2625490 (or 2625484 counting only the distinct ones).

The product of its digits is 1749600, while the sum is 52.

The spelling of 21965656912 in words is "twenty-one billion, nine hundred sixty-five million, six hundred fifty-six thousand, nine hundred twelve".