40005409 has 2 divisors, whose sum is σ = 40005410. Its totient is φ = 40005408.

The previous prime is 40005397. The next prime is 40005439. The reversal of 40005409 is 90450004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39438400 + 567009 = 6280^2 + 753^2 .

It is a cyclic number.

It is not a de Polignac number, because 40005409 - 2⁵ = 40005377 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 40005409.

It is not a weakly prime, because it can be changed into another prime (40005439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20002704 + 20002705.

It is an arithmetic number, because the mean of its divisors is an integer number (20002705).

Almost surely, 2^40005409 is an apocalyptic number.

It is an amenable number.

40005409 is a deficient number, since it is larger than the sum of its proper divisors (1).

40005409 is an equidigital number, since it uses as much as digits as its factorization.

40005409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 40005409 is about 6324.9829248781. The cubic root of 40005409 is about 342.0106040737.

It can be divided in two parts, 4000 and 5409, that added together give a square (9409 = 97²).

The spelling of 40005409 in words is "forty million, five thousand, four hundred nine".