3957391 has 4 divisors (see below), whose sum is σ = 3969472. Its totient is φ = 3945312.

The previous prime is 3957389. The next prime is 3957397. The reversal of 3957391 is 1937593.

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

It is a cyclic number.

It is not a de Polignac number, because 3957391 - 2¹ = 3957389 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3957391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3957397) 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, 5535 + ... + 6208.

It is an arithmetic number, because the mean of its divisors is an integer number (992368).

Almost surely, 2^3957391 is an apocalyptic number.

3957391 is a deficient number, since it is larger than the sum of its proper divisors (12081).

3957391 is a wasteful number, since it uses less digits than its factorization.

3957391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12080.

The product of its digits is 25515, while the sum is 37.

The square root of 3957391 is about 1989.3192302896. The cubic root of 3957391 is about 158.1744454720.

The spelling of 3957391 in words is "three million, nine hundred fifty-seven thousand, three hundred ninety-one".