405521 has 2 divisors, whose sum is σ = 405522. Its totient is φ = 405520.

The previous prime is 405499. The next prime is 405527. The reversal of 405521 is 125504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 261121 + 144400 = 511^2 + 380^2 .

It is a cyclic number.

It is not a de Polignac number, because 405521 - 2¹⁰ = 404497 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 405521.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 405521.

It is not a weakly prime, because it can be changed into another prime (405527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202760 + 202761.

It is an arithmetic number, because the mean of its divisors is an integer number (202761).

2⁴⁰⁵⁵²¹ is an apocalyptic number.

It is an amenable number.

405521 is a deficient number, since it is larger than the sum of its proper divisors (1).

405521 is an equidigital number, since it uses as much as digits as its factorization.

405521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 405521 is about 636.8053077668. The cubic root of 405521 is about 74.0180744747.

Subtracting from 405521 its sum of digits (17), we obtain a palindrome (405504).

The spelling of 405521 in words is "four hundred five thousand, five hundred twenty-one".