128698399 has 2 divisors, whose sum is σ = 128698400. Its totient is φ = 128698398.

The previous prime is 128698351. The next prime is 128698403. The reversal of 128698399 is 993896821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128698399 - 2¹⁵ = 128665631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128698309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64349199 + 64349200.

It is an arithmetic number, because the mean of its divisors is an integer number (64349200).

Almost surely, 2^128698399 is an apocalyptic number.

128698399 is a deficient number, since it is larger than the sum of its proper divisors (1).

128698399 is an equidigital number, since it uses as much as digits as its factorization.

128698399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1679616, while the sum is 55.

The square root of 128698399 is about 11344.5316783021. The cubic root of 128698399 is about 504.8833491963.

The spelling of 128698399 in words is "one hundred twenty-eight million, six hundred ninety-eight thousand, three hundred ninety-nine".