2021000221 has 4 divisors (see below), whose sum is σ = 2025668092. Its totient is φ = 2016332352.

The previous prime is 2021000147. The next prime is 2021000251. The reversal of 2021000221 is 1220001202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 68244121 + 1952756100 = 8261^2 + 44190^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021000221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021000198 and 2021000207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021000251) 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, 2333286 + ... + 2334151.

It is an arithmetic number, because the mean of its divisors is an integer number (506417023).

Almost surely, 2^2021000221 is an apocalyptic number.

It is an amenable number.

2021000221 is a deficient number, since it is larger than the sum of its proper divisors (4667871).

2021000221 is an equidigital number, since it uses as much as digits as its factorization.

2021000221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4667870.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 2021000221 is about 44955.5360439624. The cubic root of 2021000221 is about 1264.3154750281.

Adding to 2021000221 its reverse (1220001202), we get a palindrome (3241001423).

The spelling of 2021000221 in words is "two billion, twenty-one million, two hundred twenty-one", and thus it is an aban number.