128570261 has 2 divisors, whose sum is σ = 128570262. Its totient is φ = 128570260.

The previous prime is 128570251. The next prime is 128570293. The reversal of 128570261 is 162075821.

It is an a-pointer prime, because the next prime (128570293) can be obtained adding 128570261 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118679236 + 9891025 = 10894^2 + 3145^2 .

It is an emirp because it is prime and its reverse (162075821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128570261 - 2¹⁰ = 128569237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128570251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64285130 + 64285131.

It is an arithmetic number, because the mean of its divisors is an integer number (64285131).

Almost surely, 2^128570261 is an apocalyptic number.

It is an amenable number.

128570261 is a deficient number, since it is larger than the sum of its proper divisors (1).

128570261 is an equidigital number, since it uses as much as digits as its factorization.

128570261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 128570261 is about 11338.8827050993. The cubic root of 128570261 is about 504.7157319195.

The spelling of 128570261 in words is "one hundred twenty-eight million, five hundred seventy thousand, two hundred sixty-one".