2155217 has 4 divisors (see below), whose sum is σ = 2161776. Its totient is φ = 2148660.

The previous prime is 2155207. The next prime is 2155253. The reversal of 2155217 is 7125512.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2155217 - 2⁴ = 2155201 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2155192 and 2155201.

It is not an unprimeable number, because it can be changed into a prime (2155207) 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, 2759 + ... + 3452.

It is an arithmetic number, because the mean of its divisors is an integer number (540444).

2^2155217 is an apocalyptic number.

It is an amenable number.

2155217 is a deficient number, since it is larger than the sum of its proper divisors (6559).

2155217 is an equidigital number, since it uses as much as digits as its factorization.

2155217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6558.

The product of its digits is 700, while the sum is 23.

The square root of 2155217 is about 1468.0657342231. The cubic root of 2155217 is about 129.1705973599.

The spelling of 2155217 in words is "two million, one hundred fifty-five thousand, two hundred seventeen".