20211021225 has 18 divisors (see below), whose sum is σ = 36200185086. Its totient is φ = 10779211200.

The previous prime is 20211021223. The next prime is 20211021253. The reversal of 20211021225 is 52212011202.

It can be written as a sum of positive squares in 3 ways, for example, as 2672786601 + 17538234624 = 51699^2 + 132432^2 .

It is not a de Polignac number, because 20211021225 - 2¹ = 20211021223 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211021198 and 20211021207.

It is not an unprimeable number, because it can be changed into a prime (20211021223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 44913156 + ... + 44913605.

Almost surely, 2^20211021225 is an apocalyptic number.

20211021225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20211021225 is a deficient number, since it is larger than the sum of its proper divisors (15989163861).

20211021225 is a wasteful number, since it uses less digits than its factorization.

20211021225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89826777 (or 89826769 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

Adding to 20211021225 its reverse (52212011202), we get a palindrome (72423032427).

The spelling of 20211021225 in words is "twenty billion, two hundred eleven million, twenty-one thousand, two hundred twenty-five".