128799889 has 2 divisors, whose sum is σ = 128799890. Its totient is φ = 128799888.

The previous prime is 128799887. The next prime is 128799907. The reversal of 128799889 is 988997821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125440000 + 3359889 = 11200^2 + 1833^2 .

It is a cyclic number.

It is not a de Polignac number, because 128799889 - 2¹ = 128799887 is a prime.

It is a super-2 number, since 2×128799889² = 33178822812824642, which contains 22 as substring.

Together with 128799887, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (128799883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64399944 + 64399945.

It is an arithmetic number, because the mean of its divisors is an integer number (64399945).

Almost surely, 2^128799889 is an apocalyptic number.

It is an amenable number.

128799889 is a deficient number, since it is larger than the sum of its proper divisors (1).

128799889 is an equidigital number, since it uses as much as digits as its factorization.

128799889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5225472, while the sum is 61.

The square root of 128799889 is about 11349.0038769929. The cubic root of 128799889 is about 505.0160292922.

The spelling of 128799889 in words is "one hundred twenty-eight million, seven hundred ninety-nine thousand, eight hundred eighty-nine".