21456522565412 has 72 divisors (see below), whose sum is σ = 42056250369336. Its totient is φ = 9567866880000.

The previous prime is 21456522565411. The next prime is 21456522565459.

21456522565412 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 5046699348196 + 16409823217216 = 2246486^2 + 4050904^2 .

It is not an unprimeable number, because it can be changed into a prime (21456522565411) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 253938212 + ... + 254022692.

It is an arithmetic number, because the mean of its divisors is an integer number (584114588463).

Almost surely, 2^{21456522565412} is an apocalyptic number.

21456522565412 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21456522565412 is a deficient number, since it is larger than the sum of its proper divisors (20599727803924).

21456522565412 is a wasteful number, since it uses less digits than its factorization.

21456522565412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94461 (or 94448 counting only the distinct ones).

The product of its digits is 5760000, while the sum is 50.

The spelling of 21456522565412 in words is "twenty-one trillion, four hundred fifty-six billion, five hundred twenty-two million, five hundred sixty-five thousand, four hundred twelve".