3906391 has 4 divisors (see below), whose sum is σ = 3919032. Its totient is φ = 3893752.

The previous prime is 3906373. The next prime is 3906401. The reversal of 3906391 is 1936093.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1936093 = 1327 ⋅1459.

It is a cyclic number.

It is not a de Polignac number, because 3906391 - 2⁷ = 3906263 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 (3906361) 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, 5845 + ... + 6478.

It is an arithmetic number, because the mean of its divisors is an integer number (979758).

Almost surely, 2^3906391 is an apocalyptic number.

3906391 is a deficient number, since it is larger than the sum of its proper divisors (12641).

3906391 is a wasteful number, since it uses less digits than its factorization.

3906391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12640.

The product of its (nonzero) digits is 4374, while the sum is 31.

The square root of 3906391 is about 1976.4592077754. The cubic root of 3906391 is about 157.4920261353.

The spelling of 3906391 in words is "three million, nine hundred six thousand, three hundred ninety-one".