73815 has 32 divisors (see below), whose sum is σ = 145920. Its totient is φ = 31104.

The previous prime is 73783. The next prime is 73819. The reversal of 73815 is 51837.

73815 = 66² + 67² + ... + 79².

73815 is nontrivially palindromic in base 11.

73815 is a nontrivial binomial coefficient, being equal to C(38, 4).

It is not a de Polignac number, because 73815 - 2⁵ = 73783 is a prime.

It is an Ulam number.

73815 is an undulating number in base 11.

It is a plaindrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1977 + ... + 2013.

It is an arithmetic number, because the mean of its divisors is an integer number (4560).

2⁷³⁸¹⁵ is an apocalyptic number.

73815 is the 222-nd pentagonal number.

73815 is a deficient number, since it is larger than the sum of its proper divisors (72105).

73815 is a wasteful number, since it uses less digits than its factorization.

73815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71.

The product of its digits is 840, while the sum is 24.

The square root of 73815 is about 271.6891606229. The cubic root of 73815 is about 41.9483492053.

It can be divided in two parts, 73 and 815, that multiplied together give a palindrome (59495).

The spelling of 73815 in words is "seventy-three thousand, eight hundred fifteen".