2015 has 8 divisors (see below), whose sum is σ = 2688. Its totient is φ = 1440.

The previous prime is 2011. The next prime is 2017. The reversal of 2015 is 5102.

2015 is nontrivially palindromic in base 2.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2015 - 2² = 2011 is a prime.

It is a Duffinian number.

2015 is an undulating number in base 8.

It is a plaindrome in base 9, base 12 and base 16.

It is a zygodrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 1993 and 2011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50 + ... + 80.

It is an arithmetic number, because the mean of its divisors is an integer number (336).

2²⁰¹⁵ is an apocalyptic number.

2015 is a deficient number, since it is larger than the sum of its proper divisors (673).

2015 is a wasteful number, since it uses less digits than its factorization.

2015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49.

The product of its (nonzero) digits is 10, while the sum is 8.

The square root of 2015 is about 44.8887513749. Note that the first 3 decimals coincide. The cubic root of 2015 is about 12.6306301066.

Adding to 2015 its product of nonzero digits (10), we get a square (2025 = 45²).

Adding to 2015 its reverse (5102), we get a palindrome (7117).

It can be divided in two parts, 20 and 15, that multiplied together give a triangular number (300 = T₂₄).

The spelling of 2015 in words is "two thousand, fifteen".