3978431 has 2 divisors, whose sum is σ = 3978432. Its totient is φ = 3978430.

The previous prime is 3978421. The next prime is 3978433. The reversal of 3978431 is 1348793.

It is a strong prime.

It is an emirp because it is prime and its reverse (1348793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3978431 - 2¹⁴ = 3962047 is a prime.

It is a super-2 number, since 2×3978431² = 31655826443522, which contains 22 as substring.

Together with 3978433, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 3978391 and 3978400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3978433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1989215 + 1989216.

It is an arithmetic number, because the mean of its divisors is an integer number (1989216).

Almost surely, 2^3978431 is an apocalyptic number.

3978431 is a deficient number, since it is larger than the sum of its proper divisors (1).

3978431 is an equidigital number, since it uses as much as digits as its factorization.

3978431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 35.

The square root of 3978431 is about 1994.6004612453. The cubic root of 3978431 is about 158.4542687015.

The spelling of 3978431 in words is "three million, nine hundred seventy-eight thousand, four hundred thirty-one".