821864453 has 2 divisors, whose sum is σ = 821864454. Its totient is φ = 821864452.

The previous prime is 821864429. The next prime is 821864489. The reversal of 821864453 is 354468128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 794845249 + 27019204 = 28193^2 + 5198^2 .

It is a cyclic number.

It is not a de Polignac number, because 821864453 - 2¹⁶ = 821798917 is a prime.

It is a super-2 number, since 2×821864453² = 1350922358209978418, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 821864453.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821164453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410932226 + 410932227.

It is an arithmetic number, because the mean of its divisors is an integer number (410932227).

Almost surely, 2^821864453 is an apocalyptic number.

It is an amenable number.

821864453 is a deficient number, since it is larger than the sum of its proper divisors (1).

821864453 is an equidigital number, since it uses as much as digits as its factorization.

821864453 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 184320, while the sum is 41.

The square root of 821864453 is about 28668.1784039377. The cubic root of 821864453 is about 936.6990195101.

The spelling of 821864453 in words is "eight hundred twenty-one million, eight hundred sixty-four thousand, four hundred fifty-three".