673128621 has 24 divisors (see below), whose sum is σ = 1061817120. Its totient is φ = 407522400.

The previous prime is 673128607. The next prime is 673128623. The reversal of 673128621 is 126821376.

673128621 is a `hidden beast` number, since 6 + 7 + 3 + 1 + 28 + 621 = 666.

It is not a de Polignac number, because 673128621 - 2¹⁵ = 673095853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (673128623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 106726 + ... + 112856.

It is an arithmetic number, because the mean of its divisors is an integer number (44242380).

Almost surely, 2^673128621 is an apocalyptic number.

It is an amenable number.

673128621 is a deficient number, since it is larger than the sum of its proper divisors (388688499).

673128621 is a wasteful number, since it uses less digits than its factorization.

673128621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7257 (or 7254 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 673128621 is about 25944.7224113113. The cubic root of 673128621 is about 876.3939125712.

Adding to 673128621 its reverse (126821376), we get a palindrome (799949997).

The spelling of 673128621 in words is "six hundred seventy-three million, one hundred twenty-eight thousand, six hundred twenty-one".