128670308821 has 2 divisors, whose sum is σ = 128670308822. Its totient is φ = 128670308820.

The previous prime is 128670308801. The next prime is 128670308843. The reversal of 128670308821 is 128803076821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81185104900 + 47485203921 = 284930^2 + 217911^2 .

It is a cyclic number.

It is not a de Polignac number, because 128670308821 - 2⁷ = 128670308693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128670308801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64335154410 + 64335154411.

It is an arithmetic number, because the mean of its divisors is an integer number (64335154411).

Almost surely, 2^128670308821 is an apocalyptic number.

It is an amenable number.

128670308821 is a deficient number, since it is larger than the sum of its proper divisors (1).

128670308821 is an equidigital number, since it uses as much as digits as its factorization.

128670308821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 258048, while the sum is 46.

The spelling of 128670308821 in words is "one hundred twenty-eight billion, six hundred seventy million, three hundred eight thousand, eight hundred twenty-one".