2188405 has 4 divisors (see below), whose sum is σ = 2626092. Its totient is φ = 1750720.

The previous prime is 2188349. The next prime is 2188409. The reversal of 2188405 is 5048812.

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 398161 + 1790244 = 631^2 + 1338^2 .

It is not a de Polignac number, because 2188405 - 2¹⁷ = 2057333 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 (2188409) 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, 218836 + ... + 218845.

It is an arithmetic number, because the mean of its divisors is an integer number (656523).

2^2188405 is an apocalyptic number.

It is an amenable number.

2188405 is a deficient number, since it is larger than the sum of its proper divisors (437687).

2188405 is an equidigital number, since it uses as much as digits as its factorization.

2188405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437686.

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 2188405 is about 1479.3258599781. The cubic root of 2188405 is about 129.8302518197.

The spelling of 2188405 in words is "two million, one hundred eighty-eight thousand, four hundred five".