40491397 has 2 divisors, whose sum is σ = 40491398. Its totient is φ = 40491396.

The previous prime is 40491391. The next prime is 40491443. The reversal of 40491397 is 79319404.

40491397 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37344321 + 3147076 = 6111^2 + 1774^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40491397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40491391) 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 as a sum of consecutive naturals, namely, 20245698 + 20245699.

It is an arithmetic number, because the mean of its divisors is an integer number (20245699).

Almost surely, 2^40491397 is an apocalyptic number.

It is an amenable number.

40491397 is a deficient number, since it is larger than the sum of its proper divisors (1).

40491397 is an equidigital number, since it uses as much as digits as its factorization.

40491397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 40491397 is about 6363.2850792653. The cubic root of 40491397 is about 343.3899550524.

The spelling of 40491397 in words is "forty million, four hundred ninety-one thousand, three hundred ninety-seven".