40242391 has 4 divisors (see below), whose sum is σ = 45991312. Its totient is φ = 34493472.

The previous prime is 40242337. The next prime is 40242403. The reversal of 40242391 is 19324204.

40242391 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 40242391 - 2⁷ = 40242263 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 (40242311) 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, 2874450 + ... + 2874463.

It is an arithmetic number, because the mean of its divisors is an integer number (11497828).

Almost surely, 2^40242391 is an apocalyptic number.

40242391 is a deficient number, since it is larger than the sum of its proper divisors (5748921).

40242391 is an equidigital number, since it uses as much as digits as its factorization.

40242391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5748920.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 40242391 is about 6343.6890686729. The cubic root of 40242391 is about 342.6846032733.

Adding to 40242391 its reverse (19324204), we get a palindrome (59566595).

The spelling of 40242391 in words is "forty million, two hundred forty-two thousand, three hundred ninety-one".