261518 has 8 divisors (see below), whose sum is σ = 394680. Its totient is φ = 129960.

The previous prime is 261509. The next prime is 261523. The reversal of 261518 is 815162.

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

It is a junction number, because it is equal to n+sod(n) for n = 261493 and 261502.

It is a congruent number.

It is an unprimeable number.

261518 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173 + ... + 743.

It is an arithmetic number, because the mean of its divisors is an integer number (49335).

2²⁶¹⁵¹⁸ is an apocalyptic number.

261518 is a deficient number, since it is larger than the sum of its proper divisors (133162).

261518 is a wasteful number, since it uses less digits than its factorization.

261518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802.

The product of its digits is 480, while the sum is 23.

The square root of 261518 is about 511.3883064756. The cubic root of 261518 is about 63.9490153843.

The spelling of 261518 in words is "two hundred sixty-one thousand, five hundred eighteen".