21522286645 has 4 divisors (see below), whose sum is σ = 25826743980. Its totient is φ = 17217829312.

The previous prime is 21522286601. The next prime is 21522286649. The reversal of 21522286645 is 54668222512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3227830596 + 18294456049 = 56814^2 + 135257^2 .

It is a cyclic number.

It is not a de Polignac number, because 21522286645 - 2²⁹ = 20985415733 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21522286649) 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, 2152228660 + ... + 2152228669.

It is an arithmetic number, because the mean of its divisors is an integer number (6456685995).

Almost surely, 2^21522286645 is an apocalyptic number.

It is an amenable number.

21522286645 is a deficient number, since it is larger than the sum of its proper divisors (4304457335).

21522286645 is an equidigital number, since it uses as much as digits as its factorization.

21522286645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4304457334.

The product of its digits is 460800, while the sum is 43.

The spelling of 21522286645 in words is "twenty-one billion, five hundred twenty-two million, two hundred eighty-six thousand, six hundred forty-five".