128069261 has 2 divisors, whose sum is σ = 128069262. Its totient is φ = 128069260.

The previous prime is 128069239. The next prime is 128069311. The reversal of 128069261 is 162960821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 106213636 + 21855625 = 10306^2 + 4675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128069261 is a prime.

It is a super-2 number, since 2×128069261² = 32803471226172242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128069231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64034630 + 64034631.

It is an arithmetic number, because the mean of its divisors is an integer number (64034631).

Almost surely, 2^128069261 is an apocalyptic number.

It is an amenable number.

128069261 is a deficient number, since it is larger than the sum of its proper divisors (1).

128069261 is an equidigital number, since it uses as much as digits as its factorization.

128069261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 128069261 is about 11316.7690177011. The cubic root of 128069261 is about 504.0593029341.

The spelling of 128069261 in words is "one hundred twenty-eight million, sixty-nine thousand, two hundred sixty-one".