11523581 has 2 divisors, whose sum is σ = 11523582. Its totient is φ = 11523580.

The previous prime is 11523559. The next prime is 11523593. The reversal of 11523581 is 18532511.

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., 10621081 + 902500 = 3259^2 + 950^2 .

It is a cyclic number.

It is not a de Polignac number, because 11523581 - 2¹⁰ = 11522557 is a prime.

It is a super-2 number, since 2×11523581² = 265585838127122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11523581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11523181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5761790 + 5761791.

It is an arithmetic number, because the mean of its divisors is an integer number (5761791).

Almost surely, 2^11523581 is an apocalyptic number.

It is an amenable number.

11523581 is a deficient number, since it is larger than the sum of its proper divisors (1).

11523581 is an equidigital number, since it uses as much as digits as its factorization.

11523581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 26.

The square root of 11523581 is about 3394.6400398275. The cubic root of 11523581 is about 225.8720462433.

The spelling of 11523581 in words is "eleven million, five hundred twenty-three thousand, five hundred eighty-one".