128423681 has 2 divisors, whose sum is σ = 128423682. Its totient is φ = 128423680.

The previous prime is 128423579. The next prime is 128423741. The reversal of 128423681 is 186324821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95257600 + 33166081 = 9760^2 + 5759^2 .

It is an emirp because it is prime and its reverse (186324821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128423681 - 2²² = 124229377 is a prime.

It is a super-2 number, since 2×128423681² = 32985283683179522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128425681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64211840 + 64211841.

It is an arithmetic number, because the mean of its divisors is an integer number (64211841).

Almost surely, 2^128423681 is an apocalyptic number.

It is an amenable number.

128423681 is a deficient number, since it is larger than the sum of its proper divisors (1).

128423681 is an equidigital number, since it uses as much as digits as its factorization.

128423681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18432, while the sum is 35.

The square root of 128423681 is about 11332.4172619967. The cubic root of 128423681 is about 504.5238540467.

The spelling of 128423681 in words is "one hundred twenty-eight million, four hundred twenty-three thousand, six hundred eighty-one".