11981729 has 4 divisors (see below), whose sum is σ = 12087876. Its totient is φ = 11875584.

The previous prime is 11981713. The next prime is 11981743. The reversal of 11981729 is 92718911.

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 577600 + 11404129 = 760^2 + 3377^2 .

It is a cyclic number.

It is not a de Polignac number, because 11981729 - 2⁴ = 11981713 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11981692 and 11981701.

It is not an unprimeable number, because it can be changed into a prime (11981329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52904 + ... + 53129.

It is an arithmetic number, because the mean of its divisors is an integer number (3021969).

Almost surely, 2^11981729 is an apocalyptic number.

It is an amenable number.

11981729 is a deficient number, since it is larger than the sum of its proper divisors (106147).

11981729 is a wasteful number, since it uses less digits than its factorization.

11981729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106146.

The product of its digits is 9072, while the sum is 38.

The square root of 11981729 is about 3461.4634188447. The cubic root of 11981729 is about 228.8265946335.

The spelling of 11981729 in words is "eleven million, nine hundred eighty-one thousand, seven hundred twenty-nine".