3921591 has 4 divisors (see below), whose sum is σ = 5228792. Its totient is φ = 2614392.

The previous prime is 3921559. The next prime is 3921601. The reversal of 3921591 is 1951293.

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

It is not a de Polignac number, because 3921591 - 2⁵ = 3921559 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3921521) 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, 653596 + ... + 653601.

It is an arithmetic number, because the mean of its divisors is an integer number (1307198).

Almost surely, 2^3921591 is an apocalyptic number.

3921591 is a deficient number, since it is larger than the sum of its proper divisors (1307201).

3921591 is a wasteful number, since it uses less digits than its factorization.

3921591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1307200.

The product of its digits is 2430, while the sum is 30.

The square root of 3921591 is about 1980.3007347370. The cubic root of 3921591 is about 157.6960320480.

The spelling of 3921591 in words is "three million, nine hundred twenty-one thousand, five hundred ninety-one".