405804409 has 2 divisors, whose sum is σ = 405804410. Its totient is φ = 405804408.

The previous prime is 405804407. The next prime is 405804457. The reversal of 405804409 is 904408504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 251920384 + 153884025 = 15872^2 + 12405^2 .

It is a cyclic number.

It is not a de Polignac number, because 405804409 - 2¹ = 405804407 is a prime.

Together with 405804407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (405804403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202902204 + 202902205.

It is an arithmetic number, because the mean of its divisors is an integer number (202902205).

Almost surely, 2^405804409 is an apocalyptic number.

It is an amenable number.

405804409 is a deficient number, since it is larger than the sum of its proper divisors (1).

405804409 is an equidigital number, since it uses as much as digits as its factorization.

405804409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 405804409 is about 20144.5875857512. The cubic root of 405804409 is about 740.3531361764.

The spelling of 405804409 in words is "four hundred five million, eight hundred four thousand, four hundred nine".