128136791865 has 16 divisors (see below), whose sum is σ = 217078800768. Its totient is φ = 64319644416.

The previous prime is 128136791753. The next prime is 128136791879. The reversal of 128136791865 is 568197631821.

It is not a de Polignac number, because 128136791865 - 2¹¹ = 128136789817 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 251248357 + ... + 251248866.

It is an arithmetic number, because the mean of its divisors is an integer number (13567425048).

Almost surely, 2^128136791865 is an apocalyptic number.

128136791865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

128136791865 is a deficient number, since it is larger than the sum of its proper divisors (88942008903).

128136791865 is a wasteful number, since it uses less digits than its factorization.

128136791865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502497248.

The product of its digits is 4354560, while the sum is 57.

The spelling of 128136791865 in words is "one hundred twenty-eight billion, one hundred thirty-six million, seven hundred ninety-one thousand, eight hundred sixty-five".