128754457821 has 16 divisors (see below), whose sum is σ = 208088013120. Its totient is φ = 78033004560.

The previous prime is 128754457801. The next prime is 128754457823.

128754457821 is a `hidden beast` number, since 1 + 2 + 8 + 7 + 5 + 44 + 578 + 21 = 666.

128754457821 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 128754457821 - 2¹⁰ = 128754456797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128754457823) 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, 216758050 + ... + 216758643.

It is an arithmetic number, because the mean of its divisors is an integer number (13005500820).

Almost surely, 2^128754457821 is an apocalyptic number.

128754457821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

128754457821 is a deficient number, since it is larger than the sum of its proper divisors (79333555299).

128754457821 is a wasteful number, since it uses less digits than its factorization.

128754457821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433516713 (or 433516707 counting only the distinct ones).

The product of its digits is 5017600, while the sum is 54.

The spelling of 128754457821 in words is "one hundred twenty-eight billion, seven hundred fifty-four million, four hundred fifty-seven thousand, eight hundred twenty-one".