128312461 has 2 divisors, whose sum is σ = 128312462. Its totient is φ = 128312460.

The previous prime is 128312399. The next prime is 128312477. The reversal of 128312461 is 164213821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108784900 + 19527561 = 10430^2 + 4419^2 .

It is a cyclic number.

It is not a de Polignac number, because 128312461 - 2⁷ = 128312333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128312761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64156230 + 64156231.

It is an arithmetic number, because the mean of its divisors is an integer number (64156231).

Almost surely, 2^128312461 is an apocalyptic number.

It is an amenable number.

128312461 is a deficient number, since it is larger than the sum of its proper divisors (1).

128312461 is an equidigital number, since it uses as much as digits as its factorization.

128312461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 28.

The square root of 128312461 is about 11327.5090377364. The cubic root of 128312461 is about 504.3781660938.

The spelling of 128312461 in words is "one hundred twenty-eight million, three hundred twelve thousand, four hundred sixty-one".