40815 has 12 divisors (see below), whose sum is σ = 70824. Its totient is φ = 21744.

The previous prime is 40813. The next prime is 40819. The reversal of 40815 is 51804.

It is not a de Polignac number, because 40815 - 2¹ = 40813 is a prime.

40815 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 40815.

It is not an unprimeable number, because it can be changed into a prime (40813) 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, 409 + ... + 498.

It is an arithmetic number, because the mean of its divisors is an integer number (5902).

2⁴⁰⁸¹⁵ is an apocalyptic number.

40815 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

40815 is a deficient number, since it is larger than the sum of its proper divisors (30009).

40815 is a wasteful number, since it uses less digits than its factorization.

40815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 918 (or 915 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 40815 is about 202.0272258880. The cubic root of 40815 is about 34.4302307717.

The spelling of 40815 in words is "forty thousand, eight hundred fifteen".