1666817316 has 18 divisors (see below), whose sum is σ = 4213343862. Its totient is φ = 555605760.

The previous prime is 1666817303. The next prime is 1666817333. The reversal of 1666817316 is 6137186661.

It can be written as a sum of positive squares in only one way, i.e., 1392782400 + 274034916 = 37320^2 + 16554^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23150205 + ... + 23150276.

It is an arithmetic number, because the mean of its divisors is an integer number (234074659).

Almost surely, 2^1666817316 is an apocalyptic number.

It is an amenable number.

1666817316 is an abundant number, since it is smaller than the sum of its proper divisors (2546526546).

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

1666817316 is a wasteful number, since it uses less digits than its factorization.

1666817316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46300491 (or 46300486 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 1666817316 is about 40826.6740746782. The cubic root of 1666817316 is about 1185.6668233274. Note that the first 3 decimals are identical.

The spelling of 1666817316 in words is "one billion, six hundred sixty-six million, eight hundred seventeen thousand, three hundred sixteen".