4253221021 has 6 divisors (see below), whose sum is σ = 4947624510. Its totient is φ = 3645617976.

The previous prime is 4253220953. The next prime is 4253221051. The reversal of 4253221021 is 1201223524.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2353220100 + 1900000921 = 48510^2 + 43589^2 .

It is not a de Polignac number, because 4253221021 - 2¹¹ = 4253218973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4253220983 and 4253221001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4253221051) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43400166 + ... + 43400263.

It is an arithmetic number, because the mean of its divisors is an integer number (824604085).

Almost surely, 2^4253221021 is an apocalyptic number.

It is an amenable number.

4253221021 is a deficient number, since it is larger than the sum of its proper divisors (694403489).

4253221021 is an equidigital number, since it uses as much as digits as its factorization.

4253221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86800443 (or 86800436 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 4253221021 is about 65216.7234764213. The cubic root of 4253221021 is about 1620.2150074075.

Adding to 4253221021 its reverse (1201223524), we get a palindrome (5454444545).

The spelling of 4253221021 in words is "four billion, two hundred fifty-three million, two hundred twenty-one thousand, twenty-one".