3978397 has 4 divisors (see below), whose sum is σ = 4004896. Its totient is φ = 3951900.

The previous prime is 3978349. The next prime is 3978421. The reversal of 3978397 is 7938793.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7938793 = 419 ⋅18947.

It is a cyclic number.

It is not a de Polignac number, because 3978397 - 2⁷ = 3978269 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 (3978197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13023 + ... + 13324.

It is an arithmetic number, because the mean of its divisors is an integer number (1001224).

Almost surely, 2^3978397 is an apocalyptic number.

It is an amenable number.

3978397 is a deficient number, since it is larger than the sum of its proper divisors (26499).

3978397 is a wasteful number, since it uses less digits than its factorization.

3978397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26498.

The product of its digits is 285768, while the sum is 46.

The square root of 3978397 is about 1994.5919382169. The cubic root of 3978397 is about 158.4538173124.

The spelling of 3978397 in words is "three million, nine hundred seventy-eight thousand, three hundred ninety-seven".