2021645243 has 2 divisors, whose sum is σ = 2021645244. Its totient is φ = 2021645242.

The previous prime is 2021645233. The next prime is 2021645279. The reversal of 2021645243 is 3425461202.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021645243 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (2021645233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010822621 + 1010822622.

It is an arithmetic number, because the mean of its divisors is an integer number (1010822622).

Almost surely, 2^2021645243 is an apocalyptic number.

2021645243 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021645243 is an equidigital number, since it uses as much as digits as its factorization.

2021645243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 2021645243 is about 44962.7094712941. The cubic root of 2021645243 is about 1264.4499669403.

The spelling of 2021645243 in words is "two billion, twenty-one million, six hundred forty-five thousand, two hundred forty-three".