405945 has 32 divisors (see below), whose sum is σ = 752640. Its totient is φ = 207360.

The previous prime is 405917. The next prime is 405947. The reversal of 405945 is 549504.

It is not a de Polignac number, because 405945 - 2⁷ = 405817 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4137 + ... + 4233.

It is an arithmetic number, because the mean of its divisors is an integer number (23520).

2⁴⁰⁵⁹⁴⁵ is an apocalyptic number.

405945 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

405945 is a deficient number, since it is larger than the sum of its proper divisors (346695).

405945 is a wasteful number, since it uses less digits than its factorization.

405945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 405945 is about 637.1381325898. The cubic root of 405945 is about 74.0438624791.

The spelling of 405945 in words is "four hundred five thousand, nine hundred forty-five".