163815 has 16 divisors (see below), whose sum is σ = 267648. Its totient is φ = 85536.

The previous prime is 163811. The next prime is 163819. The reversal of 163815 is 518361.

163815 = 179² + 180² + ... + 183².

It is an interprime number because it is at equal distance from previous prime (163811) and next prime (163819).

It is not a de Polignac number, because 163815 - 2² = 163811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 924 + ... + 1086.

It is an arithmetic number, because the mean of its divisors is an integer number (16728).

2¹⁶³⁸¹⁵ is an apocalyptic number.

163815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

163815 is a deficient number, since it is larger than the sum of its proper divisors (103833).

163815 is a wasteful number, since it uses less digits than its factorization.

163815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238.

The product of its digits is 720, while the sum is 24.

The square root of 163815 is about 404.7406577056. The cubic root of 163815 is about 54.7164469881.

It can be divided in two parts, 1638 and 15, that added together give a triangular number (1653 = T₅₇).

The spelling of 163815 in words is "one hundred sixty-three thousand, eight hundred fifteen".