40138409 has 2 divisors, whose sum is σ = 40138410. Its totient is φ = 40138408.

The previous prime is 40138387. The next prime is 40138421. The reversal of 40138409 is 90483104.

40138409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36421225 + 3717184 = 6035^2 + 1928^2 .

It is a cyclic number.

It is not a de Polignac number, because 40138409 - 2¹² = 40134313 is a prime.

It is a super-2 number, since 2×40138409² = 3222183754102562, which contains 22 as substring.

It is a plaindrome in base 15.

It is not a weakly prime, because it can be changed into another prime (40138429) 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, 20069204 + 20069205.

It is an arithmetic number, because the mean of its divisors is an integer number (20069205).

Almost surely, 2^40138409 is an apocalyptic number.

It is an amenable number.

40138409 is a deficient number, since it is larger than the sum of its proper divisors (1).

40138409 is an equidigital number, since it uses as much as digits as its factorization.

40138409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 40138409 is about 6335.4880632829. The cubic root of 40138409 is about 342.3891953357.

The spelling of 40138409 in words is "forty million, one hundred thirty-eight thousand, four hundred nine".