40991611 has 4 divisors (see below), whose sum is σ = 41052312. Its totient is φ = 40930912.

The previous prime is 40991609. The next prime is 40991627. The reversal of 40991611 is 11619904.

It is a semiprime because it is the product of two primes.

It is a 5-Lehmer number, since φ(40991611) divides (40991611-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 40991611 - 2¹ = 40991609 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40991651) 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, 29326 + ... + 30691.

It is an arithmetic number, because the mean of its divisors is an integer number (10263078).

Almost surely, 2^40991611 is an apocalyptic number.

40991611 is a deficient number, since it is larger than the sum of its proper divisors (60701).

40991611 is an equidigital number, since it uses as much as digits as its factorization.

40991611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60700.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 40991611 is about 6402.4691330767. The cubic root of 40991611 is about 344.7982044711.

The spelling of 40991611 in words is "forty million, nine hundred ninety-one thousand, six hundred eleven".