3965581 has 2 divisors, whose sum is σ = 3965582. Its totient is φ = 3965580.

The previous prime is 3965569. The next prime is 3965587. The reversal of 3965581 is 1855693.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3880900 + 84681 = 1970^2 + 291^2 .

It is a cyclic number.

It is not a de Polignac number, because 3965581 - 2¹³ = 3957389 is a prime.

It is a super-2 number, since 2×3965581² = 31451665335122, which contains 22 as substring.

3965581 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 3965581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3965587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1982790 + 1982791.

It is an arithmetic number, because the mean of its divisors is an integer number (1982791).

Almost surely, 2^3965581 is an apocalyptic number.

It is an amenable number.

3965581 is a deficient number, since it is larger than the sum of its proper divisors (1).

3965581 is an equidigital number, since it uses as much as digits as its factorization.

3965581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 37.

The square root of 3965581 is about 1991.3766594997. The cubic root of 3965581 is about 158.2834866788.

The spelling of 3965581 in words is "three million, nine hundred sixty-five thousand, five hundred eighty-one".