3891397 has 4 divisors (see below), whose sum is σ = 3908620. Its totient is φ = 3874176.

The previous prime is 3891389. The next prime is 3891403. The reversal of 3891397 is 7931983.

3891397 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7931983 = 41 ⋅193463.

It can be written as a sum of positive squares in 2 ways, for example, as 2172676 + 1718721 = 1474^2 + 1311^2 .

It is a cyclic number.

It is not a de Polignac number, because 3891397 - 2³ = 3891389 is a prime.

It is a super-2 number, since 2×3891397² = 30285941223218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3891197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8268 + ... + 8725.

It is an arithmetic number, because the mean of its divisors is an integer number (977155).

Almost surely, 2^3891397 is an apocalyptic number.

It is an amenable number.

3891397 is a deficient number, since it is larger than the sum of its proper divisors (17223).

3891397 is a wasteful number, since it uses less digits than its factorization.

3891397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17222.

The product of its digits is 40824, while the sum is 40.

The square root of 3891397 is about 1972.6624140993. The cubic root of 3891397 is about 157.2902658901.

The spelling of 3891397 in words is "three million, eight hundred ninety-one thousand, three hundred ninety-seven".