40023791 has 2 divisors, whose sum is σ = 40023792. Its totient is φ = 40023790.

The previous prime is 40023787. The next prime is 40023793. The reversal of 40023791 is 19732004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 40023791 - 2² = 40023787 is a prime.

Together with 40023793, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 40023791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40023793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20011895 + 20011896.

It is an arithmetic number, because the mean of its divisors is an integer number (20011896).

Almost surely, 2^40023791 is an apocalyptic number.

40023791 is a deficient number, since it is larger than the sum of its proper divisors (1).

40023791 is an equidigital number, since it uses as much as digits as its factorization.

40023791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 40023791 is about 6326.4358844455. The cubic root of 40023791 is about 342.0629792934.

Adding to 40023791 its reverse (19732004), we get a palindrome (59755795).

The spelling of 40023791 in words is "forty million, twenty-three thousand, seven hundred ninety-one".