11006640581 has 4 divisors (see below), whose sum is σ = 11013534252. Its totient is φ = 10999746912.

The previous prime is 11006640577. The next prime is 11006640611. The reversal of 11006640581 is 18504660011.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18504660011 = 41 ⋅451333171.

It can be written as a sum of positive squares in 2 ways, for example, as 939729025 + 10066911556 = 30655^2 + 100334^2 .

It is a cyclic number.

It is not a de Polignac number, because 11006640581 - 2² = 11006640577 is a prime.

It is a super-2 number, since 2×11006640581² (a number of 21 digits) 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 (11006640521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3444440 + ... + 3447633.

It is an arithmetic number, because the mean of its divisors is an integer number (2753383563).

Almost surely, 2^11006640581 is an apocalyptic number.

It is an amenable number.

11006640581 is a deficient number, since it is larger than the sum of its proper divisors (6893671).

11006640581 is an equidigital number, since it uses as much as digits as its factorization.

11006640581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6893670.

The product of its (nonzero) digits is 5760, while the sum is 32.

The spelling of 11006640581 in words is "eleven billion, six million, six hundred forty thousand, five hundred eighty-one".