11961642091 has 8 divisors (see below), whose sum is σ = 13672075520. Its totient is φ = 10251615528.

The previous prime is 11961642079. The next prime is 11961642101. The reversal of 11961642091 is 19024616911.

11961642091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 11961642091 - 2⁵ = 11961642059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11961642061) 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 7 ways as a sum of consecutive naturals, for example, 35871 + ... + 158776.

It is an arithmetic number, because the mean of its divisors is an integer number (1709009440).

Almost surely, 2^11961642091 is an apocalyptic number.

11961642091 is a deficient number, since it is larger than the sum of its proper divisors (1710433429).

11961642091 is an equidigital number, since it uses as much as digits as its factorization.

11961642091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203433.

The product of its (nonzero) digits is 23328, while the sum is 40.

The spelling of 11961642091 in words is "eleven billion, nine hundred sixty-one million, six hundred forty-two thousand, ninety-one".