821288851 has 4 divisors (see below), whose sum is σ = 864514600. Its totient is φ = 778063104.

The previous prime is 821288837. The next prime is 821288869. The reversal of 821288851 is 158882128.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 821288851 - 2⁹ = 821288339 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 821288798 and 821288807.

It is not an unprimeable number, because it can be changed into a prime (821288801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21612846 + ... + 21612883.

It is an arithmetic number, because the mean of its divisors is an integer number (216128650).

Almost surely, 2^821288851 is an apocalyptic number.

821288851 is a deficient number, since it is larger than the sum of its proper divisors (43225749).

821288851 is a wasteful number, since it uses less digits than its factorization.

821288851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43225748.

The product of its digits is 81920, while the sum is 43.

The square root of 821288851 is about 28658.1376052248. The cubic root of 821288851 is about 936.4802925468.

The spelling of 821288851 in words is "eight hundred twenty-one million, two hundred eighty-eight thousand, eight hundred fifty-one".