11666516601 has 4 divisors (see below), whose sum is σ = 15555355472. Its totient is φ = 7777677732.

The previous prime is 11666516597. The next prime is 11666516621. The reversal of 11666516601 is 10661566611.

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 not a de Polignac number, because 11666516601 - 2² = 11666516597 is a prime.

It is a super-2 number, since 2×11666516601² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11666516601.

It is not an unprimeable number, because it can be changed into a prime (11666516621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1944419431 + ... + 1944419436.

It is an arithmetic number, because the mean of its divisors is an integer number (3888838868).

Almost surely, 2^11666516601 is an apocalyptic number.

It is an amenable number.

11666516601 is a deficient number, since it is larger than the sum of its proper divisors (3888838871).

11666516601 is an equidigital number, since it uses as much as digits as its factorization.

11666516601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3888838870.

The product of its (nonzero) digits is 38880, while the sum is 39.

The spelling of 11666516601 in words is "eleven billion, six hundred sixty-six million, five hundred sixteen thousand, six hundred one".