409209881 has 2 divisors, whose sum is σ = 409209882. Its totient is φ = 409209880.

The previous prime is 409209851. The next prime is 409209893. The reversal of 409209881 is 188902904.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214886281 + 194323600 = 14659^2 + 13940^2 .

It is a cyclic number.

It is not a de Polignac number, because 409209881 - 2²² = 405015577 is a prime.

It is a super-2 number, since 2×409209881² = 334905453416068322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (409209811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204604940 + 204604941.

It is an arithmetic number, because the mean of its divisors is an integer number (204604941).

Almost surely, 2^409209881 is an apocalyptic number.

It is an amenable number.

409209881 is a deficient number, since it is larger than the sum of its proper divisors (1).

409209881 is an equidigital number, since it uses as much as digits as its factorization.

409209881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 409209881 is about 20228.9367244055. The cubic root of 409209881 is about 742.4183608804.

The spelling of 409209881 in words is "four hundred nine million, two hundred nine thousand, eight hundred eighty-one".