51515 has 4 divisors (see below), whose sum is σ = 61824. Its totient is φ = 41208.

The previous prime is 51511. The next prime is 51517.

51515 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51515 - 2² = 51511 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

51515 is an undulating number in base 10.

51515 is a modest number, since divided by 1515 gives 5 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 51493 and 51502.

It is not an unprimeable number, because it can be changed into a prime (51511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5147 + ... + 5156.

It is an arithmetic number, because the mean of its divisors is an integer number (15456).

2⁵¹⁵¹⁵ is an apocalyptic number.

51515 is a deficient number, since it is larger than the sum of its proper divisors (10309).

51515 is a wasteful number, since it uses less digits than its factorization.

51515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10308.

The product of its digits is 125, while the sum is 17.

The square root of 51515 is about 226.9691609008. The cubic root of 51515 is about 37.2087060981.

The spelling of 51515 in words is "fifty-one thousand, five hundred fifteen".