128659647381 has 4 divisors (see below), whose sum is σ = 171546196512. Its totient is φ = 85773098252.

The previous prime is 128659647359. The next prime is 128659647383. The reversal of 128659647381 is 183746956821.

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 128659647381 - 2⁶ = 128659647317 is a prime.

It is a super-2 number, since 2×128659647381² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128659647383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21443274561 + ... + 21443274566.

It is an arithmetic number, because the mean of its divisors is an integer number (42886549128).

Almost surely, 2^128659647381 is an apocalyptic number.

It is an amenable number.

128659647381 is a deficient number, since it is larger than the sum of its proper divisors (42886549131).

128659647381 is an equidigital number, since it uses as much as digits as its factorization.

128659647381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42886549130.

The product of its digits is 17418240, while the sum is 60.

The spelling of 128659647381 in words is "one hundred twenty-eight billion, six hundred fifty-nine million, six hundred forty-seven thousand, three hundred eighty-one".