405761 has 4 divisors (see below), whose sum is σ = 408000. Its totient is φ = 403524.

The previous prime is 405749. The next prime is 405763. The reversal of 405761 is 167504.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 405761 - 2¹⁸ = 143617 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (405763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 821 + ... + 1218.

It is an arithmetic number, because the mean of its divisors is an integer number (102000).

2⁴⁰⁵⁷⁶¹ is an apocalyptic number.

It is an amenable number.

405761 is a deficient number, since it is larger than the sum of its proper divisors (2239).

405761 is a wasteful number, since it uses less digits than its factorization.

405761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2238.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 405761 is about 636.9937205342. The cubic root of 405761 is about 74.0326736648.

The spelling of 405761 in words is "four hundred five thousand, seven hundred sixty-one".