128856881 has 2 divisors, whose sum is σ = 128856882. Its totient is φ = 128856880.

The previous prime is 128856877. The next prime is 128856883. The reversal of 128856881 is 188658821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71233600 + 57623281 = 8440^2 + 7591^2 .

It is a cyclic number.

It is not a de Polignac number, because 128856881 - 2² = 128856877 is a prime.

It is a super-2 number, since 2×128856881² = 33208191562096322, which contains 22 as substring.

Together with 128856883, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128856883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64428440 + 64428441.

It is an arithmetic number, because the mean of its divisors is an integer number (64428441).

Almost surely, 2^128856881 is an apocalyptic number.

It is an amenable number.

128856881 is a deficient number, since it is larger than the sum of its proper divisors (1).

128856881 is an equidigital number, since it uses as much as digits as its factorization.

128856881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 245760, while the sum is 47.

The square root of 128856881 is about 11351.5144804559. The cubic root of 128856881 is about 505.0905056230.

The spelling of 128856881 in words is "one hundred twenty-eight million, eight hundred fifty-six thousand, eight hundred eighty-one".