11725581 has 16 divisors (see below), whose sum is σ = 17915904. Its totient is φ = 6682224.

The previous prime is 11725573. The next prime is 11725613. The reversal of 11725581 is 18552711.

It is not a de Polignac number, because 11725581 - 2³ = 11725573 is a prime.

It is a super-2 number, since 2×11725581² = 274978499575122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11725501) 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 in 15 ways as a sum of consecutive naturals, for example, 13156 + ... + 14018.

It is an arithmetic number, because the mean of its divisors is an integer number (1119744).

Almost surely, 2^11725581 is an apocalyptic number.

It is an amenable number.

11725581 is a deficient number, since it is larger than the sum of its proper divisors (6190323).

11725581 is an equidigital number, since it uses as much as digits as its factorization.

11725581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1520.

The product of its digits is 2800, while the sum is 30.

The square root of 11725581 is about 3424.2635704630. The cubic root of 11725581 is about 227.1841997563.

The spelling of 11725581 in words is "eleven million, seven hundred twenty-five thousand, five hundred eighty-one".