128538899 has 2 divisors, whose sum is σ = 128538900. Its totient is φ = 128538898.

The previous prime is 128538889. The next prime is 128538919. The reversal of 128538899 is 998835821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128538899 - 2¹⁶ = 128473363 is a prime.

It is a super-2 number, since 2×128538899² = 33044497112264402, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128538899.

It is not a weakly prime, because it can be changed into another prime (128538829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64269449 + 64269450.

It is an arithmetic number, because the mean of its divisors is an integer number (64269450).

Almost surely, 2^128538899 is an apocalyptic number.

128538899 is a deficient number, since it is larger than the sum of its proper divisors (1).

128538899 is an equidigital number, since it uses as much as digits as its factorization.

128538899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1244160, while the sum is 53.

The square root of 128538899 is about 11337.4996802646. The cubic root of 128538899 is about 504.6746903342.

The spelling of 128538899 in words is "one hundred twenty-eight million, five hundred thirty-eight thousand, eight hundred ninety-nine".