1618668666 has 12 divisors (see below), whose sum is σ = 3507115482. Its totient is φ = 539556216.

The previous prime is 1618668659. The next prime is 1618668671. The reversal of 1618668666 is 6668668161.

It can be written as a sum of positive squares in only one way, i.e., 1382278041 + 236390625 = 37179^2 + 15375^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 44963001 + ... + 44963036.

Almost surely, 2^1618668666 is an apocalyptic number.

1618668666 is an abundant number, since it is smaller than the sum of its proper divisors (1888446816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1618668666 is a wasteful number, since it uses less digits than its factorization.

1618668666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89926045 (or 89926042 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The square root of 1618668666 is about 40232.6815661099. The cubic root of 1618668666 is about 1174.1384760045.

The spelling of 1618668666 in words is "one billion, six hundred eighteen million, six hundred sixty-eight thousand, six hundred sixty-six".