40423991 has 4 divisors (see below), whose sum is σ = 41409984. Its totient is φ = 39438000.

The previous prime is 40423967. The next prime is 40423993. The reversal of 40423991 is 19932404.

It is a happy number.

40423991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 40423991 - 2⁶ = 40423927 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 (40423993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 492935 + ... + 493016.

It is an arithmetic number, because the mean of its divisors is an integer number (10352496).

Almost surely, 2^40423991 is an apocalyptic number.

40423991 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

40423991 is a deficient number, since it is larger than the sum of its proper divisors (985993).

40423991 is an equidigital number, since it uses as much as digits as its factorization.

40423991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985992.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 40423991 is about 6357.9863950782. The cubic root of 40423991 is about 343.1993022148.

It can be divided in two parts, 40423 and 991, that added together give a palindrome (41414).

The spelling of 40423991 in words is "forty million, four hundred twenty-three thousand, nine hundred ninety-one".