1166211961 has 4 divisors (see below), whose sum is σ = 1167816832. Its totient is φ = 1164607092.

The previous prime is 1166211931. The next prime is 1166211973. The reversal of 1166211961 is 1691126611.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1691126611 = 30707 ⋅55073.

It is a cyclic number.

It is not a de Polignac number, because 1166211961 - 2⁵ = 1166211929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1166211931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 801345 + ... + 802798.

It is an arithmetic number, because the mean of its divisors is an integer number (291954208).

Almost surely, 2^1166211961 is an apocalyptic number.

It is an amenable number.

1166211961 is a deficient number, since it is larger than the sum of its proper divisors (1604871).

1166211961 is an equidigital number, since it uses as much as digits as its factorization.

1166211961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1604870.

The product of its digits is 3888, while the sum is 34.

The square root of 1166211961 is about 34149.8456951126. The cubic root of 1166211961 is about 1052.5898159088.

The spelling of 1166211961 in words is "one billion, one hundred sixty-six million, two hundred eleven thousand, nine hundred sixty-one".