821930 has 8 divisors (see below), whose sum is σ = 1479492. Its totient is φ = 328768.

The previous prime is 821911. The next prime is 821939. The reversal of 821930 is 39128.

It can be written as a sum of positive squares in 2 ways, for example, as 687241 + 134689 = 829^2 + 367^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 821896 and 821905.

It is not an unprimeable number, because it can be changed into a prime (821939) by changing a digit.

821930 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41087 + ... + 41106.

2⁸²¹⁹³⁰ is an apocalyptic number.

821930 is a deficient number, since it is larger than the sum of its proper divisors (657562).

821930 is a wasteful number, since it uses less digits than its factorization.

821930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82200.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 821930 is about 906.6035517248. The cubic root of 821930 is about 93.6723920688.

The spelling of 821930 in words is "eight hundred twenty-one thousand, nine hundred thirty".