405121 has 6 divisors (see below), whose sum is σ = 416966. Its totient is φ = 393600.

The previous prime is 405091. The next prime is 405143. The reversal of 405121 is 121504.

It can be written as a sum of positive squares in 3 ways, for example, as 625 + 404496 = 25^2 + 636^2 .

It is not a de Polignac number, because 405121 - 2⁵ = 405089 is a prime.

It is a Duffinian number.

405121 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (405221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1561 + ... + 1801.

2⁴⁰⁵¹²¹ is an apocalyptic number.

405121 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

405121 is a deficient number, since it is larger than the sum of its proper divisors (11845).

405121 is an equidigital number, since it uses as much as digits as its factorization.

405121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 405121 is about 636.4911625467. The cubic root of 405121 is about 73.9937296854.

Adding to 405121 its reverse (121504), we get a palindrome (526625).

The spelling of 405121 in words is "four hundred five thousand, one hundred twenty-one".