11665661000 has 64 divisors (see below), whose sum is σ = 31197329280. Its totient is φ = 3999652800.

The previous prime is 11665660943. The next prime is 11665661003. The reversal of 11665661000 is 16656611.

It is not an unprimeable number, because it can be changed into a prime (11665661003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 826262 + ... + 840261.

It is an arithmetic number, because the mean of its divisors is an integer number (487458270).

Almost surely, 2^11665661000 is an apocalyptic number.

11665661000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11665661000 is an abundant number, since it is smaller than the sum of its proper divisors (19531668280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11665661000 is a wasteful number, since it uses less digits than its factorization.

11665661000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1666551 (or 1666537 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 32.

The spelling of 11665661000 in words is "eleven billion, six hundred sixty-five million, six hundred sixty-one thousand".