3904209 has 12 divisors (see below), whose sum is σ = 5657652. Its totient is φ = 2594400.

The previous prime is 3904189. The next prime is 3904217. The reversal of 3904209 is 9024093.

It can be written as a sum of positive squares in 2 ways, for example, as 1830609 + 2073600 = 1353^2 + 1440^2 .

It is not a de Polignac number, because 3904209 - 2⁷ = 3904081 is a prime.

3904209 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3904249) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3679 + ... + 4619.

It is an arithmetic number, because the mean of its divisors is an integer number (471471).

Almost surely, 2^3904209 is an apocalyptic number.

It is an amenable number.

3904209 is a deficient number, since it is larger than the sum of its proper divisors (1753443).

3904209 is a wasteful number, since it uses less digits than its factorization.

3904209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1408 (or 1405 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 3904209 is about 1975.9071334453. The cubic root of 3904209 is about 157.4626971370.

The spelling of 3904209 in words is "three million, nine hundred four thousand, two hundred nine".