1265581 has 2 divisors, whose sum is σ = 1265582. Its totient is φ = 1265580.

The previous prime is 1265573. The next prime is 1265597. The reversal of 1265581 is 1855621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 695556 + 570025 = 834^2 + 755^2 .

It is an emirp because it is prime and its reverse (1855621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1265581 - 2³ = 1265573 is a prime.

It is a super-2 number, since 2×1265581² = 3203390535122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1265521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632790 + 632791.

It is an arithmetic number, because the mean of its divisors is an integer number (632791).

2^1265581 is an apocalyptic number.

1265581 is the 712-nd centered pentagonal number.

It is an amenable number.

1265581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1265581 is an equidigital number, since it uses as much as digits as its factorization.

1265581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 28.

The square root of 1265581 is about 1124.9804442745. The cubic root of 1265581 is about 108.1674642478.

The spelling of 1265581 in words is "one million, two hundred sixty-five thousand, five hundred eighty-one".