3978407 has 4 divisors (see below), whose sum is σ = 3982440. Its totient is φ = 3974376.

The previous prime is 3978349. The next prime is 3978421. The reversal of 3978407 is 7048793.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7048793 = 1723 ⋅4091.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3978407 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 (3978497) 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, 569 + ... + 2877.

It is an arithmetic number, because the mean of its divisors is an integer number (995610).

Almost surely, 2^3978407 is an apocalyptic number.

3978407 is a deficient number, since it is larger than the sum of its proper divisors (4033).

3978407 is a wasteful number, since it uses less digits than its factorization.

3978407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4032.

The product of its (nonzero) digits is 42336, while the sum is 38.

The square root of 3978407 is about 1994.5944449938. The cubic root of 3978407 is about 158.4539500742.

The spelling of 3978407 in words is "three million, nine hundred seventy-eight thousand, four hundred seven".