1166636661 has 4 divisors (see below), whose sum is σ = 1555515552. Its totient is φ = 777757772.

The previous prime is 1166636657. The next prime is 1166636683. The reversal of 1166636661 is 1666366611.

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 a cyclic number.

It is not a de Polignac number, because 1166636661 - 2² = 1166636657 is a prime.

It is a super-2 number, since 2×1166636661² = 2722082197578457842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1166635661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194439441 + ... + 194439446.

It is an arithmetic number, because the mean of its divisors is an integer number (388878888).

Almost surely, 2^1166636661 is an apocalyptic number.

It is an amenable number.

1166636661 is a deficient number, since it is larger than the sum of its proper divisors (388878891).

1166636661 is an equidigital number, since it uses as much as digits as its factorization.

1166636661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388878890.

The product of its digits is 139968, while the sum is 42.

The square root of 1166636661 is about 34156.0633123901. The cubic root of 1166636661 is about 1052.7175744568.

The spelling of 1166636661 in words is "one billion, one hundred sixty-six million, six hundred thirty-six thousand, six hundred sixty-one".