11661890560 has 176 divisors, whose sum is σ = 29415488256. Its totient is φ = 4427743232.

The previous prime is 11661890533. The next prime is 11661890561. The reversal of 11661890560 is 6509816611.

It is a super-2 number, since 2×11661890560² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11661890561) 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 15 ways as a sum of consecutive naturals, for example, 19665624 + ... + 19666216.

It is an arithmetic number, because the mean of its divisors is an integer number (167133456).

Almost surely, 2^11661890560 is an apocalyptic number.

11661890560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11661890560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14707744128).

11661890560 is an abundant number, since it is smaller than the sum of its proper divisors (17753597696).

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

11661890560 is a wasteful number, since it uses less digits than its factorization.

11661890560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 808 (or 790 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 43.

The spelling of 11661890560 in words is "eleven billion, six hundred sixty-one million, eight hundred ninety thousand, five hundred sixty".