1818661605 has 16 divisors (see below), whose sum is σ = 2910727680. Its totient is φ = 969663168.

The previous prime is 1818661591. The next prime is 1818661631. The reversal of 1818661605 is 5061668181.

1818661605 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1818661605 - 2⁵ = 1818661573 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39756 + ... + 72234.

It is an arithmetic number, because the mean of its divisors is an integer number (181920480).

Almost surely, 2^1818661605 is an apocalyptic number.

1818661605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1818661605 is a deficient number, since it is larger than the sum of its proper divisors (1092066075).

1818661605 is a wasteful number, since it uses less digits than its factorization.

1818661605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36220.

The product of its (nonzero) digits is 69120, while the sum is 42.

The square root of 1818661605 is about 42645.7688991534. The cubic root of 1818661605 is about 1220.6297933014.

The spelling of 1818661605 in words is "one billion, eight hundred eighteen million, six hundred sixty-one thousand, six hundred five".