405261 has 12 divisors (see below), whose sum is σ = 601692. Its totient is φ = 262656.

The previous prime is 405253. The next prime is 405269. The reversal of 405261 is 162504.

It is a happy number.

405261 is a `hidden beast` number, since 405 + 261 = 666.

It is an interprime number because it is at equal distance from previous prime (405253) and next prime (405269).

It can be written as a sum of positive squares in 2 ways, for example, as 260100 + 145161 = 510^2 + 381^2 .

It is not a de Polignac number, because 405261 - 2³ = 405253 is a prime.

405261 is a lucky number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405269) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 276 + ... + 941.

It is an arithmetic number, because the mean of its divisors is an integer number (50141).

2⁴⁰⁵²⁶¹ is an apocalyptic number.

It is an amenable number.

405261 is a deficient number, since it is larger than the sum of its proper divisors (196431).

405261 is a wasteful number, since it uses less digits than its factorization.

405261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1260 (or 1257 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 405261 is about 636.6011310075. The cubic root of 405261 is about 74.0022521837.

Adding to 405261 its reverse (162504), we get a palindrome (567765).

It can be divided in two parts, 405 and 261, that added together give a palindrome (666).

The spelling of 405261 in words is "four hundred five thousand, two hundred sixty-one".