128371939 has 2 divisors, whose sum is σ = 128371940. Its totient is φ = 128371938.

The previous prime is 128371891. The next prime is 128371949. The reversal of 128371939 is 939173821.

It is a strong prime.

It is an emirp because it is prime and its reverse (939173821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128371939 - 2¹³ = 128363747 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128371895 and 128371904.

It is not a weakly prime, because it can be changed into another prime (128371949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64185969 + 64185970.

It is an arithmetic number, because the mean of its divisors is an integer number (64185970).

Almost surely, 2^128371939 is an apocalyptic number.

128371939 is a deficient number, since it is larger than the sum of its proper divisors (1).

128371939 is an equidigital number, since it uses as much as digits as its factorization.

128371939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 43.

The square root of 128371939 is about 11330.1341121807. The cubic root of 128371939 is about 504.4560872616.

The spelling of 128371939 in words is "one hundred twenty-eight million, three hundred seventy-one thousand, nine hundred thirty-nine".