1163581 has 2 divisors, whose sum is σ = 1163582. Its totient is φ = 1163580.

The previous prime is 1163557. The next prime is 1163587. The reversal of 1163581 is 1853611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1136356 + 27225 = 1066^2 + 165^2 .

It is an emirp because it is prime and its reverse (1853611) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1163581 - 2⁹ = 1163069 is a prime.

It is a super-2 number, since 2×1163581² = 2707841487122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1163587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 581790 + 581791.

It is an arithmetic number, because the mean of its divisors is an integer number (581791).

2^1163581 is an apocalyptic number.

It is an amenable number.

1163581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1163581 is an equidigital number, since it uses as much as digits as its factorization.

1163581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 25.

The square root of 1163581 is about 1078.6941179037. The cubic root of 1163581 is about 105.1797676349.

It can be divided in two parts, 1163 and 581, that multiplied together give a triangular number (675703 = T₁₁₆₂).

The spelling of 1163581 in words is "one million, one hundred sixty-three thousand, five hundred eighty-one".