3809921 has 4 divisors (see below), whose sum is σ = 4034052. Its totient is φ = 3585792.

The previous prime is 3809917. The next prime is 3809941. The reversal of 3809921 is 1299083.

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 2686321 + 1123600 = 1639^2 + 1060^2 .

It is a cyclic number.

It is not a de Polignac number, because 3809921 - 2² = 3809917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3809941) 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, 112040 + ... + 112073.

It is an arithmetic number, because the mean of its divisors is an integer number (1008513).

Almost surely, 2^3809921 is an apocalyptic number.

It is an amenable number.

3809921 is a deficient number, since it is larger than the sum of its proper divisors (224131).

3809921 is a wasteful number, since it uses less digits than its factorization.

3809921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224130.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 3809921 is about 1951.9018930264. The cubic root of 3809921 is about 156.1847608178.

It can be divided in two parts, 380 and 9921, that added together give a palindrome (10301).

The spelling of 3809921 in words is "three million, eight hundred nine thousand, nine hundred twenty-one".