2171221217 has 12 divisors (see below), whose sum is σ = 2394215460. Its totient is φ = 1967496960.

The previous prime is 2171221111. The next prime is 2171221223. The reversal of 2171221217 is 7121221712.

It can be written as a sum of positive squares in 2 ways, for example, as 40844881 + 2130376336 = 6391^2 + 46156^2 .

It is not a de Polignac number, because 2171221217 - 2²⁴ = 2154444001 is a prime.

It is a super-2 number, since 2×2171221217² = 9428403146301922178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2171221237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9209 + ... + 66537.

It is an arithmetic number, because the mean of its divisors is an integer number (199517955).

Almost surely, 2^2171221217 is an apocalyptic number.

It is an amenable number.

2171221217 is a deficient number, since it is larger than the sum of its proper divisors (222994243).

2171221217 is a wasteful number, since it uses less digits than its factorization.

2171221217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57664 (or 57653 counting only the distinct ones).

The product of its digits is 784, while the sum is 26.

The square root of 2171221217 is about 46596.3648474857. The cubic root of 2171221217 is about 1294.8954099279.

Adding to 2171221217 its reverse (7121221712), we get a palindrome (9292442929).

The spelling of 2171221217 in words is "two billion, one hundred seventy-one million, two hundred twenty-one thousand, two hundred seventeen".