40605661 has 8 divisors (see below), whose sum is σ = 41124600. Its totient is φ = 40089600.

The previous prime is 40605659. The next prime is 40605683. The reversal of 40605661 is 16650604.

It can be written as a sum of positive squares in 4 ways, for example, as 9803161 + 30802500 = 3131^2 + 5550^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 40605661 - 2¹ = 40605659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40605161) 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 7 ways as a sum of consecutive naturals, for example, 43245 + ... + 44173.

It is an arithmetic number, because the mean of its divisors is an integer number (5140575).

Almost surely, 2^40605661 is an apocalyptic number.

It is an amenable number.

40605661 is a deficient number, since it is larger than the sum of its proper divisors (518939).

40605661 is a wasteful number, since it uses less digits than its factorization.

40605661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 40605661 is about 6372.2571354270. The cubic root of 40605661 is about 343.7126594811.

The spelling of 40605661 in words is "forty million, six hundred five thousand, six hundred sixty-one".