128711666 has 8 divisors (see below), whose sum is σ = 196710444. Its totient is φ = 63141520.

The previous prime is 128711663. The next prime is 128711699. The reversal of 128711666 is 666117821.

It can be written as a sum of positive squares in 2 ways, for example, as 128482225 + 229441 = 11335^2 + 479^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (128711663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 607025 + ... + 607236.

Almost surely, 2^128711666 is an apocalyptic number.

128711666 is a deficient number, since it is larger than the sum of its proper divisors (67998778).

128711666 is a wasteful number, since it uses less digits than its factorization.

128711666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1214316.

The product of its digits is 24192, while the sum is 38.

The square root of 128711666 is about 11345.1163942905. The cubic root of 128711666 is about 504.9006973977.

The spelling of 128711666 in words is "one hundred twenty-eight million, seven hundred eleven thousand, six hundred sixty-six".