40002491 has 2 divisors, whose sum is σ = 40002492. Its totient is φ = 40002490.

The previous prime is 40002481. The next prime is 40002559. The reversal of 40002491 is 19420004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40002491 - 2¹⁸ = 39740347 is a prime.

It is not a weakly prime, because it can be changed into another prime (40002421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20001245 + 20001246.

It is an arithmetic number, because the mean of its divisors is an integer number (20001246).

Almost surely, 2^40002491 is an apocalyptic number.

40002491 is a deficient number, since it is larger than the sum of its proper divisors (1).

40002491 is an equidigital number, since it uses as much as digits as its factorization.

40002491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 40002491 is about 6324.7522481122. The cubic root of 40002491 is about 342.0022884381.

Adding to 40002491 its reverse (19420004), we get a palindrome (59422495).

The spelling of 40002491 in words is "forty million, two thousand, four hundred ninety-one".