13913665128 has 72 divisors (see below), whose sum is σ = 41420010450. Its totient is φ = 4216259520.

The previous prime is 13913665123. The next prime is 13913665177. The reversal of 13913665128 is 82156631931.

13913665128 is a `hidden beast` number, since 13 + 91 + 36 + 6 + 512 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13294551204 + 619113924 = 115302^2 + 24882^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (13913665121) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 789823 + ... + 807246.

Almost surely, 2^13913665128 is an apocalyptic number.

13913665128 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

13913665128 is an abundant number, since it is smaller than the sum of its proper divisors (27506345322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13913665128 is a wasteful number, since it uses less digits than its factorization.

13913665128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1597103 (or 1597085 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The spelling of 13913665128 in words is "thirteen billion, nine hundred thirteen million, six hundred sixty-five thousand, one hundred twenty-eight".