133815 has 16 divisors (see below), whose sum is σ = 233856. Its totient is φ = 64800.

The previous prime is 133813. The next prime is 133831. The reversal of 133815 is 518331.

It is a happy number.

133815 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 133815 - 2¹ = 133813 is a prime.

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 133791 and 133800.

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 133815.

It is not an unprimeable number, because it can be changed into a prime (133811) 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, 241 + ... + 570.

It is an arithmetic number, because the mean of its divisors is an integer number (14616).

133815 is a Friedman number, since it can be written as 811*33*5, using all its digits and the basic arithmetic operations.

2¹³³⁸¹⁵ is an apocalyptic number.

133815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

133815 is a deficient number, since it is larger than the sum of its proper divisors (100041).

133815 is a wasteful number, since it uses less digits than its factorization.

133815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830.

The product of its digits is 360, while the sum is 21.

The square root of 133815 is about 365.8073263345. The cubic root of 133815 is about 51.1487391821.

It can be divided in two parts, 13 and 3815, that added together give a triangular number (3828 = T₈₇).

The spelling of 133815 in words is "one hundred thirty-three thousand, eight hundred fifteen".