21564261412 has 24 divisors (see below), whose sum is σ = 38765149304. Its totient is φ = 10488621312.

The previous prime is 21564261403. The next prime is 21564261419. The reversal of 21564261412 is 21416246512.

It can be written as a sum of positive squares in 4 ways, for example, as 5043272256 + 16520989156 = 71016^2 + 128534^2 .

It is not an unprimeable number, because it can be changed into a prime (21564261419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 935368 + ... + 958144.

Almost surely, 2^21564261412 is an apocalyptic number.

It is an amenable number.

21564261412 is a deficient number, since it is larger than the sum of its proper divisors (17200887892).

21564261412 is a wasteful number, since it uses less digits than its factorization.

21564261412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29215 (or 29213 counting only the distinct ones).

The product of its digits is 23040, while the sum is 34.

The spelling of 21564261412 in words is "twenty-one billion, five hundred sixty-four million, two hundred sixty-one thousand, four hundred twelve".