821928308 has 12 divisors (see below), whose sum is σ = 1522984932. Its totient is φ = 386789760.

The previous prime is 821928301. The next prime is 821928313. The reversal of 821928308 is 803829128.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 727488784 + 94439524 = 26972^2 + 9718^2 .

It is a super-2 number, since 2×821928308² = 1351132286983485728, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821928301) 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, 6043523 + ... + 6043658.

It is an arithmetic number, because the mean of its divisors is an integer number (126915411).

Almost surely, 2^821928308 is an apocalyptic number.

It is an amenable number.

821928308 is a deficient number, since it is larger than the sum of its proper divisors (701056624).

821928308 is a wasteful number, since it uses less digits than its factorization.

821928308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12087202 (or 12087200 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 821928308 is about 28669.2920735759. The cubic root of 821928308 is about 936.7232779170.

The spelling of 821928308 in words is "eight hundred twenty-one million, nine hundred twenty-eight thousand, three hundred eight".