2158817 has 2 divisors, whose sum is σ = 2158818. Its totient is φ = 2158816.

The previous prime is 2158811. The next prime is 2158823. The reversal of 2158817 is 7188512.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (2158811) and next prime (2158823).

It can be written as a sum of positive squares in only one way, i.e., 2062096 + 96721 = 1436^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 2158817 - 2⁴ = 2158801 is a prime.

It is a Chen prime.

It is equal to p₁₅₉₈₈₁ and since 2158817 and 159881 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (2158811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1079408 + 1079409.

It is an arithmetic number, because the mean of its divisors is an integer number (1079409).

2^2158817 is an apocalyptic number.

It is an amenable number.

2158817 is a deficient number, since it is larger than the sum of its proper divisors (1).

2158817 is an equidigital number, since it uses as much as digits as its factorization.

2158817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 32.

The square root of 2158817 is about 1469.2913257758. The cubic root of 2158817 is about 129.2424780531.

The spelling of 2158817 in words is "two million, one hundred fifty-eight thousand, eight hundred seventeen".