40866809 has 4 divisors (see below), whose sum is σ = 40879716. Its totient is φ = 40853904.

The previous prime is 40866803. The next prime is 40866811. The reversal of 40866809 is 90866804.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 861184 + 40005625 = 928^2 + 6325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40866809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40866803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1907 + ... + 9239.

It is an arithmetic number, because the mean of its divisors is an integer number (10219929).

Almost surely, 2^40866809 is an apocalyptic number.

It is an amenable number.

40866809 is a deficient number, since it is larger than the sum of its proper divisors (12907).

40866809 is an equidigital number, since it uses as much as digits as its factorization.

40866809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12906.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 40866809 is about 6392.7153072853. The cubic root of 40866809 is about 344.4479275132.

The spelling of 40866809 in words is "forty million, eight hundred sixty-six thousand, eight hundred nine".