11989961 has 4 divisors (see below), whose sum is σ = 12314052. Its totient is φ = 11665872.

The previous prime is 11989951. The next prime is 11989973. The reversal of 11989961 is 16998911.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4177936 + 7812025 = 2044^2 + 2795^2 .

It is a cyclic number.

It is not a de Polignac number, because 11989961 - 2⁶ = 11989897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11989951) 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, 161990 + ... + 162063.

It is an arithmetic number, because the mean of its divisors is an integer number (3078513).

Almost surely, 2^11989961 is an apocalyptic number.

It is an amenable number.

11989961 is a deficient number, since it is larger than the sum of its proper divisors (324091).

11989961 is an equidigital number, since it uses as much as digits as its factorization.

11989961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324090.

The product of its digits is 34992, while the sum is 44.

The square root of 11989961 is about 3462.6523071195. The cubic root of 11989961 is about 228.8789874419.

The spelling of 11989961 in words is "eleven million, nine hundred eighty-nine thousand, nine hundred sixty-one".