40685561 has 4 divisors (see below), whose sum is σ = 46497792. Its totient is φ = 34873332.

The previous prime is 40685543. The next prime is 40685569. The reversal of 40685561 is 16558604.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40685561 - 2⁶ = 40685497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (40685569) 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, 2906105 + ... + 2906118.

It is an arithmetic number, because the mean of its divisors is an integer number (11624448).

Almost surely, 2^40685561 is an apocalyptic number.

It is an amenable number.

40685561 is a deficient number, since it is larger than the sum of its proper divisors (5812231).

40685561 is an equidigital number, since it uses as much as digits as its factorization.

40685561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5812230.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 40685561 is about 6378.5234184723. The cubic root of 40685561 is about 343.9379535878.

The spelling of 40685561 in words is "forty million, six hundred eighty-five thousand, five hundred sixty-one".