2166145 has 4 divisors (see below), whose sum is σ = 2599380. Its totient is φ = 1732912.

The previous prime is 2166137. The next prime is 2166161. The reversal of 2166145 is 5416612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 848241 + 1317904 = 921^2 + 1148^2 .

It is a cyclic number.

It is not a de Polignac number, because 2166145 - 2³ = 2166137 is a prime.

It is a super-2 number, since 2×2166145² = 9384368322050, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 216610 + ... + 216619.

It is an arithmetic number, because the mean of its divisors is an integer number (649845).

2^2166145 is an apocalyptic number.

It is an amenable number.

2166145 is a deficient number, since it is larger than the sum of its proper divisors (433235).

2166145 is an equidigital number, since it uses as much as digits as its factorization.

2166145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433234.

The product of its digits is 1440, while the sum is 25.

The square root of 2166145 is about 1471.7829323647. The cubic root of 2166145 is about 129.3885486834.

It can be divided in two parts, 21 and 66145, that added together give a palindrome (66166).

The spelling of 2166145 in words is "two million, one hundred sixty-six thousand, one hundred forty-five".