128997 has 12 divisors (see below), whose sum is σ = 203424. Its totient is φ = 78120.

The previous prime is 128993. The next prime is 129001. The reversal of 128997 is 799821.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (128993) and next prime (129001).

It is not a de Polignac number, because 128997 - 2² = 128993 is a prime.

128997 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 553 + ... + 750.

It is an arithmetic number, because the mean of its divisors is an integer number (16952).

2¹²⁸⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

128997 is a deficient number, since it is larger than the sum of its proper divisors (74427).

128997 is a wasteful number, since it uses less digits than its factorization.

128997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1320 (or 1317 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 128997 is about 359.1615235517. The cubic root of 128997 is about 50.5273517811.

It can be divided in two parts, 12 and 8997, that added together give a palindrome (9009).

The spelling of 128997 in words is "one hundred twenty-eight thousand, nine hundred ninety-seven".