128997797 has 2 divisors, whose sum is σ = 128997798. Its totient is φ = 128997796.

The previous prime is 128997787. The next prime is 128997811. The reversal of 128997797 is 797799821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122190916 + 6806881 = 11054^2 + 2609^2 .

It is a cyclic number.

It is not a de Polignac number, because 128997797 - 2¹⁰ = 128996773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128997787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64498898 + 64498899.

It is an arithmetic number, because the mean of its divisors is an integer number (64498899).

Almost surely, 2^128997797 is an apocalyptic number.

It is an amenable number.

128997797 is a deficient number, since it is larger than the sum of its proper divisors (1).

128997797 is an equidigital number, since it uses as much as digits as its factorization.

128997797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4000752, while the sum is 59.

The square root of 128997797 is about 11357.7197095192. The cubic root of 128997797 is about 505.2745584094.

The spelling of 128997797 in words is "one hundred twenty-eight million, nine hundred ninety-seven thousand, seven hundred ninety-seven".