128513315821 has 16 divisors (see below), whose sum is σ = 153561925440. Its totient is φ = 106166260480.

The previous prime is 128513315713. The next prime is 128513315839.

It is a happy number.

128513315821 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 128513315821 - 2⁹ = 128513315309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128513315221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11843491 + ... + 11854336.

It is an arithmetic number, because the mean of its divisors is an integer number (9597620340).

Almost surely, 2^128513315821 is an apocalyptic number.

128513315821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

128513315821 is a deficient number, since it is larger than the sum of its proper divisors (25048609619).

128513315821 is a wasteful number, since it uses less digits than its factorization.

128513315821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23697884.

The product of its digits is 57600, while the sum is 40.

The spelling of 128513315821 in words is "one hundred twenty-eight billion, five hundred thirteen million, three hundred fifteen thousand, eight hundred twenty-one".