1166661065997 has 80 divisors (see below), whose sum is σ = 1997835282432. Its totient is φ = 664633499040.

The previous prime is 1166661065953. The next prime is 1166661066029. The reversal of 1166661065997 is 7995601666611.

It is not a de Polignac number, because 1166661065997 - 2²⁰ = 1166660017421 is a prime.

It is a super-2 number, since 2×1166661065997² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1166661065597) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 295879608 + ... + 295883550.

Almost surely, 2^{1166661065997} is an apocalyptic number.

It is an amenable number.

1166661065997 is a deficient number, since it is larger than the sum of its proper divisors (831174216435).

1166661065997 is an equidigital number, since it uses as much as digits as its factorization.

1166661065997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5420 (or 5411 counting only the distinct ones).

The product of its (nonzero) digits is 22044960, while the sum is 63.

The spelling of 1166661065997 in words is "one trillion, one hundred sixty-six billion, six hundred sixty-one million, sixty-five thousand, nine hundred ninety-seven".