404451809 has 2 divisors, whose sum is σ = 404451810. Its totient is φ = 404451808.

The previous prime is 404451799. The next prime is 404451821. The reversal of 404451809 is 908154404.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 264550225 + 139901584 = 16265^2 + 11828^2 .

It is a cyclic number.

It is not a de Polignac number, because 404451809 - 2¹⁶ = 404386273 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (404451869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202225904 + 202225905.

It is an arithmetic number, because the mean of its divisors is an integer number (202225905).

Almost surely, 2^404451809 is an apocalyptic number.

It is an amenable number.

404451809 is a deficient number, since it is larger than the sum of its proper divisors (1).

404451809 is an equidigital number, since it uses as much as digits as its factorization.

404451809 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 35.

The square root of 404451809 is about 20110.9872706439. The cubic root of 404451809 is about 739.5296554582.

The spelling of 404451809 in words is "four hundred four million, four hundred fifty-one thousand, eight hundred nine".