828648391 has 4 divisors (see below), whose sum is σ = 877392432. Its totient is φ = 779904352.

The previous prime is 828648377. The next prime is 828648421. The reversal of 828648391 is 193846828.

828648391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-828648391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (828648341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24371995 + ... + 24372028.

It is an arithmetic number, because the mean of its divisors is an integer number (219348108).

Almost surely, 2^828648391 is an apocalyptic number.

828648391 is a deficient number, since it is larger than the sum of its proper divisors (48744041).

828648391 is a wasteful number, since it uses less digits than its factorization.

828648391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48744040.

The product of its digits is 663552, while the sum is 49.

The square root of 828648391 is about 28786.2535075338. The cubic root of 828648391 is about 939.2692339885.

The spelling of 828648391 in words is "eight hundred twenty-eight million, six hundred forty-eight thousand, three hundred ninety-one".