408209381 has 2 divisors, whose sum is σ = 408209382. Its totient is φ = 408209380.

The previous prime is 408209327. The next prime is 408209393. The reversal of 408209381 is 183902804.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 407676481 + 532900 = 20191^2 + 730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-408209381 is a prime.

It is a super-2 number, since 2×408209381² = 333269797472806322, which contains 22 as substring.

It is a Chen prime.

It is equal to p_21750497 and since 408209381 and 21750497 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (408202381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204104690 + 204104691.

It is an arithmetic number, because the mean of its divisors is an integer number (204104691).

Almost surely, 2^408209381 is an apocalyptic number.

It is an amenable number.

408209381 is a deficient number, since it is larger than the sum of its proper divisors (1).

408209381 is an equidigital number, since it uses as much as digits as its factorization.

408209381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 408209381 is about 20204.1921640040. The cubic root of 408209381 is about 741.8128071123.

The spelling of 408209381 in words is "four hundred eight million, two hundred nine thousand, three hundred eighty-one".