11650655581 has 4 divisors (see below), whose sum is σ = 12263848000. Its totient is φ = 11037463164.

The previous prime is 11650655551. The next prime is 11650655593. The reversal of 11650655581 is 18555605611.

It is a happy number.

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 11650655581 - 2⁷ = 11650655453 is a prime.

It is a super-2 number, since 2×11650655581² (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 (11650655501) 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, 306596181 + ... + 306596218.

It is an arithmetic number, because the mean of its divisors is an integer number (3065962000).

Almost surely, 2^11650655581 is an apocalyptic number.

It is an amenable number.

11650655581 is a deficient number, since it is larger than the sum of its proper divisors (613192419).

11650655581 is an equidigital number, since it uses as much as digits as its factorization.

11650655581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 613192418.

The product of its (nonzero) digits is 180000, while the sum is 43.

The spelling of 11650655581 in words is "eleven billion, six hundred fifty million, six hundred fifty-five thousand, five hundred eighty-one".