1660665518 has 4 divisors (see below), whose sum is σ = 2490998280. Its totient is φ = 830332758.

The previous prime is 1660665509. The next prime is 1660665521. The reversal of 1660665518 is 8155660661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8155660661 = 43 ⋅189666527.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415166378 + ... + 415166381.

It is an arithmetic number, because the mean of its divisors is an integer number (622749570).

Almost surely, 2^1660665518 is an apocalyptic number.

1660665518 is a deficient number, since it is larger than the sum of its proper divisors (830332762).

1660665518 is an equidigital number, since it uses as much as digits as its factorization.

1660665518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830332761.

The product of its (nonzero) digits is 259200, while the sum is 44.

The square root of 1660665518 is about 40751.2640049361. The cubic root of 1660665518 is about 1184.2063604085.

The spelling of 1660665518 in words is "one billion, six hundred sixty million, six hundred sixty-five thousand, five hundred eighteen".