2166835221 has 24 divisors (see below), whose sum is σ = 3437853120. Its totient is φ = 1309023936.

The previous prime is 2166835189. The next prime is 2166835243. The reversal of 2166835221 is 1225386612.

It is not a de Polignac number, because 2166835221 - 2⁵ = 2166835189 is a prime.

It is a super-2 number, since 2×2166835221² = 9390349749932237682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166835261) 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 23 ways as a sum of consecutive naturals, for example, 271536 + ... + 279401.

It is an arithmetic number, because the mean of its divisors is an integer number (143243880).

Almost surely, 2^2166835221 is an apocalyptic number.

It is an amenable number.

2166835221 is a deficient number, since it is larger than the sum of its proper divisors (1271017899).

2166835221 is a wasteful number, since it uses less digits than its factorization.

2166835221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550985 (or 550982 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 2166835221 is about 46549.2773413294. The cubic root of 2166835221 is about 1294.0229002411.

The spelling of 2166835221 in words is "two billion, one hundred sixty-six million, eight hundred thirty-five thousand, two hundred twenty-one".