11666989 has 2 divisors, whose sum is σ = 11666990. Its totient is φ = 11666988.

The previous prime is 11666987. The next prime is 11666999. The reversal of 11666989 is 98966611.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7382089 + 4284900 = 2717^2 + 2070^2 .

It is a cyclic number.

It is not a de Polignac number, because 11666989 - 2¹ = 11666987 is a prime.

It is a super-2 number, since 2×11666989² = 272237264652242, which contains 22 as substring.

Together with 11666987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11666983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5833494 + 5833495.

It is an arithmetic number, because the mean of its divisors is an integer number (5833495).

Almost surely, 2^11666989 is an apocalyptic number.

It is an amenable number.

11666989 is a deficient number, since it is larger than the sum of its proper divisors (1).

11666989 is an equidigital number, since it uses as much as digits as its factorization.

11666989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 46.

The square root of 11666989 is about 3415.6974397625. The cubic root of 11666989 is about 226.8051592608.

The spelling of 11666989 in words is "eleven million, six hundred sixty-six thousand, nine hundred eighty-nine".