11911961 has 4 divisors (see below), whose sum is σ = 12003024. Its totient is φ = 11820900.

The previous prime is 11911931. The next prime is 11911969. The reversal of 11911961 is 16911911.

It is a happy number.

11911961 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

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 11911961 - 2¹⁰ = 11910937 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11911969) 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, 45335 + ... + 45596.

It is an arithmetic number, because the mean of its divisors is an integer number (3000756).

Almost surely, 2^11911961 is an apocalyptic number.

11911961 is the 1544-th centered decagonal number.

It is an amenable number.

11911961 is a deficient number, since it is larger than the sum of its proper divisors (91063).

11911961 is an equidigital number, since it uses as much as digits as its factorization.

11911961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91062.

The product of its digits is 486, while the sum is 29.

The square root of 11911961 is about 3451.3708870534. The cubic root of 11911961 is about 228.3815875899.

The spelling of 11911961 in words is "eleven million, nine hundred eleven thousand, nine hundred sixty-one".