40161561 has 8 divisors (see below), whose sum is σ = 58416864. Its totient is φ = 24340320.

The previous prime is 40161559. The next prime is 40161571. The reversal of 40161561 is 16516104.

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

It is not a de Polignac number, because 40161561 - 2¹ = 40161559 is a prime.

It is a super-2 number, since 2×40161561² = 3225901963913442, which contains 22 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (40161551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 608476 + ... + 608541.

It is an arithmetic number, because the mean of its divisors is an integer number (7302108).

Almost surely, 2^40161561 is an apocalyptic number.

It is an amenable number.

40161561 is a deficient number, since it is larger than the sum of its proper divisors (18255303).

40161561 is a wasteful number, since it uses less digits than its factorization.

40161561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217031.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 40161561 is about 6337.3149677131. The cubic root of 40161561 is about 342.4550131831.

Adding to 40161561 its reverse (16516104), we get a palindrome (56677665).

The spelling of 40161561 in words is "forty million, one hundred sixty-one thousand, five hundred sixty-one".