128997535 has 4 divisors (see below), whose sum is σ = 154797048. Its totient is φ = 103198024.

The previous prime is 128997511. The next prime is 128997553. The reversal of 128997535 is 535799821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 535799821 = 929 ⋅576749.

It is a cyclic number.

It is not a de Polignac number, because 128997535 - 2¹¹ = 128995487 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12899749 + ... + 12899758.

It is an arithmetic number, because the mean of its divisors is an integer number (38699262).

Almost surely, 2^128997535 is an apocalyptic number.

128997535 is a deficient number, since it is larger than the sum of its proper divisors (25799513).

128997535 is an equidigital number, since it uses as much as digits as its factorization.

128997535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25799512.

The product of its digits is 680400, while the sum is 49.

The square root of 128997535 is about 11357.7081755079. The cubic root of 128997535 is about 505.2742163312.

The spelling of 128997535 in words is "one hundred twenty-eight million, nine hundred ninety-seven thousand, five hundred thirty-five".