128660671 has 4 divisors (see below), whose sum is σ = 128803432. Its totient is φ = 128517912.

The previous prime is 128660659. The next prime is 128660677. The reversal of 128660671 is 176066821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128660671 - 2¹⁵ = 128627903 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128660671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128660677) 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, 70020 + ... + 71833.

It is an arithmetic number, because the mean of its divisors is an integer number (32200858).

Almost surely, 2^128660671 is an apocalyptic number.

128660671 is a deficient number, since it is larger than the sum of its proper divisors (142761).

128660671 is an equidigital number, since it uses as much as digits as its factorization.

128660671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142760.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 128660671 is about 11342.8687288534. The cubic root of 128660671 is about 504.8340087725.

The spelling of 128660671 in words is "one hundred twenty-eight million, six hundred sixty thousand, six hundred seventy-one".