128135791 has 8 divisors (see below), whose sum is σ = 154148480. Its totient is φ = 104050008.

The previous prime is 128135663. The next prime is 128135797. The reversal of 128135791 is 197531821.

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

It is a cyclic number.

It is not a de Polignac number, because 128135791 - 2⁷ = 128135663 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 128135791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128135797) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 481581 + ... + 481846.

It is an arithmetic number, because the mean of its divisors is an integer number (19268560).

Almost surely, 2^128135791 is an apocalyptic number.

128135791 is a deficient number, since it is larger than the sum of its proper divisors (26012689).

128135791 is an equidigital number, since it uses as much as digits as its factorization.

128135791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 963453.

The product of its digits is 15120, while the sum is 37.

The square root of 128135791 is about 11319.7080792748. The cubic root of 128135791 is about 504.1465714945.

The spelling of 128135791 in words is "one hundred twenty-eight million, one hundred thirty-five thousand, seven hundred ninety-one".