1666670738 has 16 divisors (see below), whose sum is σ = 2543733720. Its totient is φ = 818845056.

The previous prime is 1666670723. The next prime is 1666670741. The reversal of 1666670738 is 8370766661.

It can be written as a sum of positive squares in 4 ways, for example, as 1577122369 + 89548369 = 39713^2 + 9463^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18056 + ... + 60492.

Almost surely, 2^1666670738 is an apocalyptic number.

1666670738 is a deficient number, since it is larger than the sum of its proper divisors (877062982).

1666670738 is a wasteful number, since it uses less digits than its factorization.

1666670738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42781.

The product of its (nonzero) digits is 1524096, while the sum is 50.

The square root of 1666670738 is about 40824.8789098020. The cubic root of 1666670738 is about 1185.6320669158.

The spelling of 1666670738 in words is "one billion, six hundred sixty-six million, six hundred seventy thousand, seven hundred thirty-eight".