128494686719 has 4 divisors (see below), whose sum is σ = 146851070544. Its totient is φ = 110138302896.

The previous prime is 128494686637. The next prime is 128494686739. The reversal of 128494686719 is 917686494821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128494686719 is a prime.

It is a super-2 number, since 2×128494686719² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128494686739) 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, 9178191902 + ... + 9178191915.

It is an arithmetic number, because the mean of its divisors is an integer number (36712767636).

Almost surely, 2^128494686719 is an apocalyptic number.

128494686719 is a deficient number, since it is larger than the sum of its proper divisors (18356383825).

128494686719 is an equidigital number, since it uses as much as digits as its factorization.

128494686719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18356383824.

The product of its digits is 41803776, while the sum is 65.

The spelling of 128494686719 in words is "one hundred twenty-eight billion, four hundred ninety-four million, six hundred eighty-six thousand, seven hundred nineteen".