40565561 has 4 divisors (see below), whose sum is σ = 40667124. Its totient is φ = 40464000.

The previous prime is 40565543. The next prime is 40565573. The reversal of 40565561 is 16556504.

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 39137536 + 1428025 = 6256^2 + 1195^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40565561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40565521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50180 + ... + 50981.

It is an arithmetic number, because the mean of its divisors is an integer number (10166781).

Almost surely, 2^40565561 is an apocalyptic number.

It is an amenable number.

40565561 is a deficient number, since it is larger than the sum of its proper divisors (101563).

40565561 is a wasteful number, since it uses less digits than its factorization.

40565561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101562.

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 40565561 is about 6369.1099064155. The cubic root of 40565561 is about 343.5994780767.

The spelling of 40565561 in words is "forty million, five hundred sixty-five thousand, five hundred sixty-one".