128726399 has 2 divisors, whose sum is σ = 128726400. Its totient is φ = 128726398.

The previous prime is 128726369. The next prime is 128726401. The reversal of 128726399 is 993627821.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (993627821) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128726399 is a prime.

Together with 128726401, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128726369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64363199 + 64363200.

It is an arithmetic number, because the mean of its divisors is an integer number (64363200).

Almost surely, 2^128726399 is an apocalyptic number.

128726399 is a deficient number, since it is larger than the sum of its proper divisors (1).

128726399 is an equidigital number, since it uses as much as digits as its factorization.

128726399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 47.

The square root of 128726399 is about 11345.7656859288. The cubic root of 128726399 is about 504.9199611739.

The spelling of 128726399 in words is "one hundred twenty-eight million, seven hundred twenty-six thousand, three hundred ninety-nine".