2865581 has 2 divisors, whose sum is σ = 2865582. Its totient is φ = 2865580.

The previous prime is 2865559. The next prime is 2865587. The reversal of 2865581 is 1855682.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1729225 + 1136356 = 1315^2 + 1066^2 .

It is a cyclic number.

It is not a de Polignac number, because 2865581 - 2¹⁰ = 2864557 is a prime.

It is a super-2 number, since 2×2865581² = 16423108935122, which contains 22 as substring.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2865587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1432790 + 1432791.

It is an arithmetic number, because the mean of its divisors is an integer number (1432791).

2^2865581 is an apocalyptic number.

It is an amenable number.

2865581 is a deficient number, since it is larger than the sum of its proper divisors (1).

2865581 is an equidigital number, since it uses as much as digits as its factorization.

2865581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19200, while the sum is 35.

The square root of 2865581 is about 1692.8027055744. The cubic root of 2865581 is about 142.0378957246.

The spelling of 2865581 in words is "two million, eight hundred sixty-five thousand, five hundred eighty-one".