3971945 has 4 divisors (see below), whose sum is σ = 4766340. Its totient is φ = 3177552.

The previous prime is 3971917. The next prime is 3971963. The reversal of 3971945 is 5491793.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 692224 + 3279721 = 832^2 + 1811^2 .

It is a cyclic number.

It is not a de Polignac number, because 3971945 - 2⁶ = 3971881 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 3971899 and 3971908.

It is an unprimeable number.

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, 397190 + ... + 397199.

It is an arithmetic number, because the mean of its divisors is an integer number (1191585).

Almost surely, 2^3971945 is an apocalyptic number.

It is an amenable number.

3971945 is a deficient number, since it is larger than the sum of its proper divisors (794395).

3971945 is an equidigital number, since it uses as much as digits as its factorization.

3971945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794394.

The product of its digits is 34020, while the sum is 38.

The square root of 3971945 is about 1992.9739085096. The cubic root of 3971945 is about 158.3681130122.

The spelling of 3971945 in words is "three million, nine hundred seventy-one thousand, nine hundred forty-five".