11569981 has 2 divisors, whose sum is σ = 11569982. Its totient is φ = 11569980.

The previous prime is 11569973. The next prime is 11569991. The reversal of 11569981 is 18996511.

11569981 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 weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6579225 + 4990756 = 2565^2 + 2234^2 .

It is a cyclic number.

It is not a de Polignac number, because 11569981 - 2³ = 11569973 is a prime.

It is a super-2 number, since 2×11569981² = 267728920680722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11569991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5784990 + 5784991.

It is an arithmetic number, because the mean of its divisors is an integer number (5784991).

Almost surely, 2^11569981 is an apocalyptic number.

It is an amenable number.

11569981 is a deficient number, since it is larger than the sum of its proper divisors (1).

11569981 is an equidigital number, since it uses as much as digits as its factorization.

11569981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 40.

The square root of 11569981 is about 3401.4674774279. The cubic root of 11569981 is about 226.1748001560.

The spelling of 11569981 in words is "eleven million, five hundred sixty-nine thousand, nine hundred eighty-one".