128765997 has 8 divisors (see below), whose sum is σ = 190764480. Its totient is φ = 85843980.

The previous prime is 128765981. The next prime is 128765999. The reversal of 128765997 is 799567821.

It is not a de Polignac number, because 128765997 - 2⁴ = 128765981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128765999) 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, 2384529 + ... + 2384582.

It is an arithmetic number, because the mean of its divisors is an integer number (23845560).

Almost surely, 2^128765997 is an apocalyptic number.

It is an amenable number.

128765997 is a deficient number, since it is larger than the sum of its proper divisors (61998483).

128765997 is an equidigital number, since it uses as much as digits as its factorization.

128765997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4769120 (or 4769114 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 54.

The square root of 128765997 is about 11347.5106080585. The cubic root of 128765997 is about 504.9717292934.

The spelling of 128765997 in words is "one hundred twenty-eight million, seven hundred sixty-five thousand, nine hundred ninety-seven".