128938501 has 2 divisors, whose sum is σ = 128938502. Its totient is φ = 128938500.

The previous prime is 128938499. The next prime is 128938543. The reversal of 128938501 is 105839821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 116618401 + 12320100 = 10799^2 + 3510^2 .

It is a cyclic number.

It is not a de Polignac number, because 128938501 - 2¹ = 128938499 is a prime.

Together with 128938499, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128938571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64469250 + 64469251.

It is an arithmetic number, because the mean of its divisors is an integer number (64469251).

Almost surely, 2^128938501 is an apocalyptic number.

It is an amenable number.

128938501 is a deficient number, since it is larger than the sum of its proper divisors (1).

128938501 is an equidigital number, since it uses as much as digits as its factorization.

128938501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 128938501 is about 11355.1090263370. The cubic root of 128938501 is about 505.1971272368.

The spelling of 128938501 in words is "one hundred twenty-eight million, nine hundred thirty-eight thousand, five hundred one".