128464821 has 12 divisors (see below), whose sum is σ = 193628448. Its totient is φ = 81919464.

The previous prime is 128464811. The next prime is 128464877.

128464821 is a `hidden beast` number, since 1 + 2 + 8 + 4 + 648 + 2 + 1 = 666.

128464821 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 128464821 - 2⁵ = 128464789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128464811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 310095 + ... + 310508.

It is an arithmetic number, because the mean of its divisors is an integer number (16135704).

Almost surely, 2^128464821 is an apocalyptic number.

It is an amenable number.

128464821 is a deficient number, since it is larger than the sum of its proper divisors (65163627).

128464821 is a wasteful number, since it uses less digits than its factorization.

128464821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 620632 (or 620629 counting only the distinct ones).

The product of its digits is 24576, while the sum is 36.

The square root of 128464821 is about 11334.2322633692. The cubic root of 128464821 is about 504.5777223447.

The spelling of 128464821 in words is "one hundred twenty-eight million, four hundred sixty-four thousand, eight hundred twenty-one".