40409840491 has 2 divisors, whose sum is σ = 40409840492. Its totient is φ = 40409840490.

The previous prime is 40409840459. The next prime is 40409840539. The reversal of 40409840491 is 19404890404.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40409840491 - 2⁵ = 40409840459 is a prime.

It is not a weakly prime, because it can be changed into another prime (40409840441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20204920245 + 20204920246.

It is an arithmetic number, because the mean of its divisors is an integer number (20204920246).

Almost surely, 2^40409840491 is an apocalyptic number.

40409840491 is a deficient number, since it is larger than the sum of its proper divisors (1).

40409840491 is an equidigital number, since it uses as much as digits as its factorization.

40409840491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 43.

The spelling of 40409840491 in words is "forty billion, four hundred nine million, eight hundred forty thousand, four hundred ninety-one".