821970 has 24 divisors (see below), whose sum is σ = 2137356. Its totient is φ = 219168.

The previous prime is 821941. The next prime is 821971. The reversal of 821970 is 79128.

It can be written as a sum of positive squares in 2 ways, for example, as 815409 + 6561 = 903^2 + 81^2 .

It is not an unprimeable number, because it can be changed into a prime (821971) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4477 + ... + 4656.

2⁸²¹⁹⁷⁰ is an apocalyptic number.

821970 is an abundant number, since it is smaller than the sum of its proper divisors (1315386).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821970 is a wasteful number, since it uses less digits than its factorization.

821970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9146 (or 9143 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 821970 is about 906.6256118156. The cubic root of 821970 is about 93.6739115960.

The spelling of 821970 in words is "eight hundred twenty-one thousand, nine hundred seventy".