405869 has 2 divisors, whose sum is σ = 405870. Its totient is φ = 405868.

The previous prime is 405863. The next prime is 405871. The reversal of 405869 is 968504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 405769 + 100 = 637^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 405869 - 2¹² = 401773 is a prime.

It is a super-2 number, since 2×405869² = 329459290322, which contains 22 as substring.

Together with 405871, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 405869.

It is not a weakly prime, because it can be changed into another prime (405863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202934 + 202935.

It is an arithmetic number, because the mean of its divisors is an integer number (202935).

2⁴⁰⁵⁸⁶⁹ is an apocalyptic number.

It is an amenable number.

405869 is a deficient number, since it is larger than the sum of its proper divisors (1).

405869 is an equidigital number, since it uses as much as digits as its factorization.

405869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 405869 is about 637.0784881002. The cubic root of 405869 is about 74.0392414222.

The spelling of 405869 in words is "four hundred five thousand, eight hundred sixty-nine".