3978257 has 2 divisors, whose sum is σ = 3978258. Its totient is φ = 3978256.

The previous prime is 3978253. The next prime is 3978263. The reversal of 3978257 is 7528793.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2193361 + 1784896 = 1481^2 + 1336^2 .

It is an emirp because it is prime and its reverse (7528793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3978257 - 2² = 3978253 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3978253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1989128 + 1989129.

It is an arithmetic number, because the mean of its divisors is an integer number (1989129).

Almost surely, 2^3978257 is an apocalyptic number.

It is an amenable number.

3978257 is a deficient number, since it is larger than the sum of its proper divisors (1).

3978257 is an equidigital number, since it uses as much as digits as its factorization.

3978257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 105840, while the sum is 41.

The square root of 3978257 is about 1994.5568430105. The cubic root of 3978257 is about 158.4519586246.

The spelling of 3978257 in words is "three million, nine hundred seventy-eight thousand, two hundred fifty-seven".