3970991 has 2 divisors, whose sum is σ = 3970992. Its totient is φ = 3970990.

The previous prime is 3970949. The next prime is 3970997. The reversal of 3970991 is 1990793.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 3970991 - 2¹⁸ = 3708847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3970997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1985495 + 1985496.

It is an arithmetic number, because the mean of its divisors is an integer number (1985496).

Almost surely, 2^3970991 is an apocalyptic number.

3970991 is a deficient number, since it is larger than the sum of its proper divisors (1).

3970991 is an equidigital number, since it uses as much as digits as its factorization.

3970991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15309, while the sum is 38.

The square root of 3970991 is about 1992.7345533211. The cubic root of 3970991 is about 158.3554328033.

The spelling of 3970991 in words is "three million, nine hundred seventy thousand, nine hundred ninety-one".