40031591 has 4 divisors (see below), whose sum is σ = 40538400. Its totient is φ = 39524784.

The previous prime is 40031567. The next prime is 40031597. The reversal of 40031591 is 19513004.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40031591 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 (40031597) 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, 253286 + ... + 253443.

It is an arithmetic number, because the mean of its divisors is an integer number (10134600).

Almost surely, 2^40031591 is an apocalyptic number.

40031591 is a deficient number, since it is larger than the sum of its proper divisors (506809).

40031591 is an equidigital number, since it uses as much as digits as its factorization.

40031591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 506808.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 40031591 is about 6327.0523152571. The cubic root of 40031591 is about 342.0851987273.

Adding to 40031591 its reverse (19513004), we get a palindrome (59544595).

The spelling of 40031591 in words is "forty million, thirty-one thousand, five hundred ninety-one".