3261581 has 2 divisors, whose sum is σ = 3261582. Its totient is φ = 3261580.

The previous prime is 3261553. The next prime is 3261617. The reversal of 3261581 is 1851623.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2941225 + 320356 = 1715^2 + 566^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3261581 is a prime.

It is a super-2 number, since 2×3261581² = 21275821239122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p₂₃₄₃₅₉ and since 3261581 and 234359 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3261581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3261551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1630790 + 1630791.

It is an arithmetic number, because the mean of its divisors is an integer number (1630791).

Almost surely, 2^3261581 is an apocalyptic number.

It is an amenable number.

3261581 is a deficient number, since it is larger than the sum of its proper divisors (1).

3261581 is an equidigital number, since it uses as much as digits as its factorization.

3261581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 26.

The square root of 3261581 is about 1805.9847729148. The cubic root of 3261581 is about 148.3005367321.

The spelling of 3261581 in words is "three million, two hundred sixty-one thousand, five hundred eighty-one".