3957781 has 2 divisors, whose sum is σ = 3957782. Its totient is φ = 3957780.

The previous prime is 3957773. The next prime is 3957799. The reversal of 3957781 is 1877593.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2588881 + 1368900 = 1609^2 + 1170^2 .

It is a cyclic number.

It is not a de Polignac number, because 3957781 - 2³ = 3957773 is a prime.

It is a super-2 number, since 2×3957781² = 31328060887922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3957761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1978890 + 1978891.

It is an arithmetic number, because the mean of its divisors is an integer number (1978891).

Almost surely, 2^3957781 is an apocalyptic number.

It is an amenable number.

3957781 is a deficient number, since it is larger than the sum of its proper divisors (1).

3957781 is an equidigital number, since it uses as much as digits as its factorization.

3957781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52920, while the sum is 40.

The square root of 3957781 is about 1989.4172513578. The cubic root of 3957781 is about 158.1796413201.

The spelling of 3957781 in words is "three million, nine hundred fifty-seven thousand, seven hundred eighty-one".