40591 has 2 divisors, whose sum is σ = 40592. Its totient is φ = 40590.

The previous prime is 40583. The next prime is 40597. The reversal of 40591 is 19504.

40591 = T₁₆₃ + T₁₆₄ + T₁₆₅.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 40591 - 2³ = 40583 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20295 + 20296.

It is an arithmetic number, because the mean of its divisors is an integer number (20296).

2⁴⁰⁵⁹¹ is an apocalyptic number.

40591 is the 165-th centered triangular number.

40591 is a deficient number, since it is larger than the sum of its proper divisors (1).

40591 is an equidigital number, since it uses as much as digits as its factorization.

40591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 40591 is about 201.4720824333. The cubic root of 40591 is about 34.3671287763.

It can be divided in two parts, 405 and 91, that added together give a triangular number (496 = T₃₁).

The spelling of 40591 in words is "forty thousand, five hundred ninety-one".