821534213 has 2 divisors, whose sum is σ = 821534214. Its totient is φ = 821534212.

The previous prime is 821534191. The next prime is 821534227. The reversal of 821534213 is 312435128.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 477728449 + 343805764 = 21857^2 + 18542^2 .

It is a cyclic number.

It is not a de Polignac number, because 821534213 - 2⁸ = 821533957 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821534513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410767106 + 410767107.

It is an arithmetic number, because the mean of its divisors is an integer number (410767107).

Almost surely, 2^821534213 is an apocalyptic number.

It is an amenable number.

821534213 is a deficient number, since it is larger than the sum of its proper divisors (1).

821534213 is an equidigital number, since it uses as much as digits as its factorization.

821534213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 29.

The square root of 821534213 is about 28662.4181289716. The cubic root of 821534213 is about 936.5735418337.

The spelling of 821534213 in words is "eight hundred twenty-one million, five hundred thirty-four thousand, two hundred thirteen".