11661166550 has 24 divisors (see below), whose sum is σ = 23661568152. Its totient is φ = 4240424000.

The previous prime is 11661166529. The next prime is 11661166579. The reversal of 11661166550 is 5566116611.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10600511 + ... + 10601610.

It is an arithmetic number, because the mean of its divisors is an integer number (985898673).

Almost surely, 2^11661166550 is an apocalyptic number.

11661166550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

11661166550 is an abundant number, since it is smaller than the sum of its proper divisors (12000401602).

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

11661166550 is a wasteful number, since it uses less digits than its factorization.

11661166550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21202144 (or 21202139 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 38.

The spelling of 11661166550 in words is "eleven billion, six hundred sixty-one million, one hundred sixty-six thousand, five hundred fifty".