128192681 has 8 divisors (see below), whose sum is σ = 129486504. Its totient is φ = 126904320.

The previous prime is 128192671. The next prime is 128192689. The reversal of 128192681 is 186291821.

It can be written as a sum of positive squares in 4 ways, for example, as 9709456 + 118483225 = 3116^2 + 10885^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128192681 - 2²² = 123998377 is a prime.

It is a super-2 number, since 2×128192681² = 32866726923935522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128192689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58241 + ... + 60401.

It is an arithmetic number, because the mean of its divisors is an integer number (16185813).

Almost surely, 2^128192681 is an apocalyptic number.

It is an amenable number.

128192681 is a deficient number, since it is larger than the sum of its proper divisors (1293823).

128192681 is a wasteful number, since it uses less digits than its factorization.

128192681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2731.

The product of its digits is 13824, while the sum is 38.

The square root of 128192681 is about 11322.2206744084. The cubic root of 128192681 is about 504.2211711430.

The spelling of 128192681 in words is "one hundred twenty-eight million, one hundred ninety-two thousand, six hundred eighty-one".