11642581 has 4 divisors (see below), whose sum is σ = 11661664. Its totient is φ = 11623500.

The previous prime is 11642557. The next prime is 11642591. The reversal of 11642581 is 18524611.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11642581 - 2⁵ = 11642549 is a prime.

It is a super-2 number, since 2×11642581² = 271099384683122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11642591) 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 3 ways as a sum of consecutive naturals, for example, 8595 + ... + 9856.

It is an arithmetic number, because the mean of its divisors is an integer number (2915416).

Almost surely, 2^11642581 is an apocalyptic number.

It is an amenable number.

11642581 is a deficient number, since it is larger than the sum of its proper divisors (19083).

11642581 is an equidigital number, since it uses as much as digits as its factorization.

11642581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19082.

The product of its digits is 1920, while the sum is 28.

The square root of 11642581 is about 3412.1226531296. The cubic root of 11642581 is about 226.6468857690.

The spelling of 11642581 in words is "eleven million, six hundred forty-two thousand, five hundred eighty-one".