40391723 has 2 divisors, whose sum is σ = 40391724. Its totient is φ = 40391722.

The previous prime is 40391719. The next prime is 40391801. The reversal of 40391723 is 32719304.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40391723 - 2² = 40391719 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (40391713) 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 as a sum of consecutive naturals, namely, 20195861 + 20195862.

It is an arithmetic number, because the mean of its divisors is an integer number (20195862).

Almost surely, 2^40391723 is an apocalyptic number.

40391723 is a deficient number, since it is larger than the sum of its proper divisors (1).

40391723 is an equidigital number, since it uses as much as digits as its factorization.

40391723 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 40391723 is about 6355.4482926069. The cubic root of 40391723 is about 343.1079595675.

It can be divided in two parts, 40391 and 723, that added together give a palindrome (41114).

The spelling of 40391723 in words is "forty million, three hundred ninety-one thousand, seven hundred twenty-three".