21522222017 has 4 divisors (see below), whose sum is σ = 21522731460. Its totient is φ = 21521712576.

The previous prime is 21522222011. The next prime is 21522222019. The reversal of 21522222017 is 71022222512.

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 15815326081 + 5706895936 = 125759^2 + 75544^2 .

It is a cyclic number.

It is not a de Polignac number, because 21522222017 - 2¹⁸ = 21521959873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21522222011) 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, 184988 + ... + 277965.

It is an arithmetic number, because the mean of its divisors is an integer number (5380682865).

Almost surely, 2^21522222017 is an apocalyptic number.

It is an amenable number.

21522222017 is a deficient number, since it is larger than the sum of its proper divisors (509443).

21522222017 is an equidigital number, since it uses as much as digits as its factorization.

21522222017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509442.

The product of its (nonzero) digits is 2240, while the sum is 26.

Adding to 21522222017 its reverse (71022222512), we get a palindrome (92544444529).

The spelling of 21522222017 in words is "twenty-one billion, five hundred twenty-two million, two hundred twenty-two thousand, seventeen".