821863201 has 2 divisors, whose sum is σ = 821863202. Its totient is φ = 821863200.

The previous prime is 821863123. The next prime is 821863213. The reversal of 821863201 is 102368128.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 584672400 + 237190801 = 24180^2 + 15401^2 .

It is a cyclic number.

It is not a de Polignac number, because 821863201 - 2⁷ = 821863073 is a prime.

It is not a weakly prime, because it can be changed into another prime (821867201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410931600 + 410931601.

It is an arithmetic number, because the mean of its divisors is an integer number (410931601).

Almost surely, 2^821863201 is an apocalyptic number.

It is an amenable number.

821863201 is a deficient number, since it is larger than the sum of its proper divisors (1).

821863201 is an equidigital number, since it uses as much as digits as its factorization.

821863201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 821863201 is about 28668.1565678716. The cubic root of 821863201 is about 936.6985438649.

The spelling of 821863201 in words is "eight hundred twenty-one million, eight hundred sixty-three thousand, two hundred one".