128144681 has 4 divisors (see below), whose sum is σ = 146451072. Its totient is φ = 109838292.

The previous prime is 128144677. The next prime is 128144719. The reversal of 128144681 is 186441821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128144681 - 2² = 128144677 is a prime.

It is a super-2 number, since 2×128144681² = 32842118537183522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128144581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9153185 + ... + 9153198.

It is an arithmetic number, because the mean of its divisors is an integer number (36612768).

Almost surely, 2^128144681 is an apocalyptic number.

It is an amenable number.

128144681 is a deficient number, since it is larger than the sum of its proper divisors (18306391).

128144681 is an equidigital number, since it uses as much as digits as its factorization.

128144681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18306390.

The product of its digits is 12288, while the sum is 35.

The square root of 128144681 is about 11320.1007504350. The cubic root of 128144681 is about 504.1582303744.

The spelling of 128144681 in words is "one hundred twenty-eight million, one hundred forty-four thousand, six hundred eighty-one".