3791981 has 2 divisors, whose sum is σ = 3791982. Its totient is φ = 3791980.

The previous prime is 3791959. The next prime is 3792017. The reversal of 3791981 is 1891973.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3724900 + 67081 = 1930^2 + 259^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3791981 is a prime.

It is a super-2 number, since 2×3791981² = 28758239808722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3791911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1895990 + 1895991.

It is an arithmetic number, because the mean of its divisors is an integer number (1895991).

Almost surely, 2^3791981 is an apocalyptic number.

It is an amenable number.

3791981 is a deficient number, since it is larger than the sum of its proper divisors (1).

3791981 is an equidigital number, since it uses as much as digits as its factorization.

3791981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608, while the sum is 38.

The square root of 3791981 is about 1947.3009526008. The cubic root of 3791981 is about 155.9392295622.

The spelling of 3791981 in words is "three million, seven hundred ninety-one thousand, nine hundred eighty-one".