409659881 has 2 divisors, whose sum is σ = 409659882. Its totient is φ = 409659880.

The previous prime is 409659871. The next prime is 409659883. The reversal of 409659881 is 188956904.

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., 405659881 + 4000000 = 20141^2 + 2000^2 .

It is a cyclic number.

It is not a de Polignac number, because 409659881 - 2²⁶ = 342551017 is a prime.

It is a super-2 number, since 2×409659881² = 335642436201868322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 409659883, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (409659883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204829940 + 204829941.

It is an arithmetic number, because the mean of its divisors is an integer number (204829941).

Almost surely, 2^409659881 is an apocalyptic number.

It is an amenable number.

409659881 is a deficient number, since it is larger than the sum of its proper divisors (1).

409659881 is an equidigital number, since it uses as much as digits as its factorization.

409659881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 50.

The square root of 409659881 is about 20240.0563487358. The cubic root of 409659881 is about 742.6904021069.

The spelling of 409659881 in words is "four hundred nine million, six hundred fifty-nine thousand, eight hundred eighty-one".