2164861 has 4 divisors (see below), whose sum is σ = 2195424. Its totient is φ = 2134300.

The previous prime is 2164859. The next prime is 2164901. The reversal of 2164861 is 1684612.

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 2164861 - 2¹ = 2164859 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 (2164801) 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, 15175 + ... + 15316.

It is an arithmetic number, because the mean of its divisors is an integer number (548856).

2^2164861 is an apocalyptic number.

It is an amenable number.

2164861 is a deficient number, since it is larger than the sum of its proper divisors (30563).

2164861 is an equidigital number, since it uses as much as digits as its factorization.

2164861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30562.

The product of its digits is 2304, while the sum is 28.

The square root of 2164861 is about 1471.3466620753. The cubic root of 2164861 is about 129.3629782601.

Subtracting from 2164861 its reverse (1684612), we obtain a square (480249 = 693²).

It can be divided in two parts, 2164 and 861, that added together give a square (3025 = 55²).

The spelling of 2164861 in words is "two million, one hundred sixty-four thousand, eight hundred sixty-one".