2171855 has 8 divisors (see below), whose sum is σ = 2978592. Its totient is φ = 1489248.

The previous prime is 2171843. The next prime is 2171857. The reversal of 2171855 is 5581712.

2171855 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2171855 - 2⁸ = 2171599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2171857) 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 7 ways as a sum of consecutive naturals, for example, 30992 + ... + 31061.

It is an arithmetic number, because the mean of its divisors is an integer number (372324).

2^2171855 is an apocalyptic number.

2171855 is a deficient number, since it is larger than the sum of its proper divisors (806737).

2171855 is an equidigital number, since it uses as much as digits as its factorization.

2171855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62065.

The product of its digits is 2800, while the sum is 29.

The square root of 2171855 is about 1473.7214797919. The cubic root of 2171855 is about 129.5021391695.

Adding to 2171855 its product of digits (2800), we get a triangular number (2174655 = T₂₀₈₅).

The spelling of 2171855 in words is "two million, one hundred seventy-one thousand, eight hundred fifty-five".