2022020821 has 4 divisors (see below), whose sum is σ = 2071338444. Its totient is φ = 1972703200.

The previous prime is 2022020779. The next prime is 2022020839. The reversal of 2022020821 is 1280202202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1280202202 = 2 ⋅640101101.

It can be written as a sum of positive squares in 2 ways, for example, as 808264900 + 1213755921 = 28430^2 + 34839^2 .

It is a cyclic number.

It is not a de Polignac number, because 2022020821 - 2⁹ = 2022020309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2022023821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24658750 + ... + 24658831.

It is an arithmetic number, because the mean of its divisors is an integer number (517834611).

Almost surely, 2^2022020821 is an apocalyptic number.

It is an amenable number.

2022020821 is a deficient number, since it is larger than the sum of its proper divisors (49317623).

2022020821 is an equidigital number, since it uses as much as digits as its factorization.

2022020821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49317622.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 2022020821 is about 44966.8858272396. The cubic root of 2022020821 is about 1264.5282645851.

It can be divided in two parts, 20220 and 20821, that added together give a triangular number (41041 = T₂₈₆).

The spelling of 2022020821 in words is "two billion, twenty-two million, twenty thousand, eight hundred twenty-one".