518661 has 36 divisors (see below), whose sum is σ = 913536. Its totient is φ = 280800.

The previous prime is 518657. The next prime is 518689. The reversal of 518661 is 166815.

518661 = T₃ + T₄ + ... + T₁₄₅.

It is not a de Polignac number, because 518661 - 2² = 518657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (518611) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 16716 + ... + 16746.

It is an arithmetic number, because the mean of its divisors is an integer number (25376).

2⁵¹⁸⁶⁶¹ is an apocalyptic number.

It is an amenable number.

518661 is a deficient number, since it is larger than the sum of its proper divisors (394875).

518661 is a wasteful number, since it uses less digits than its factorization.

518661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 58 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 518661 is about 720.1812271922. The cubic root of 518661 is about 80.3454333838.

The spelling of 518661 in words is "five hundred eighteen thousand, six hundred sixty-one".