20221100021 has 12 divisors (see below), whose sum is σ = 20616578892. Its totient is φ = 19832776128.

The previous prime is 20221099991. The next prime is 20221100033. The reversal of 20221100021 is 12000112202.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12340099396 + 7881000625 = 111086^2 + 88775^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20221100021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20221099975 and 20221100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20221100051) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1036271 + ... + 1055603.

It is an arithmetic number, because the mean of its divisors is an integer number (1718048241).

Almost surely, 2^20221100021 is an apocalyptic number.

It is an amenable number.

20221100021 is a deficient number, since it is larger than the sum of its proper divisors (395478871).

20221100021 is an equidigital number, since it uses as much as digits as its factorization.

20221100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19700 (or 19633 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20221100021 its reverse (12000112202), we get a palindrome (32221212223).

The spelling of 20221100021 in words is "twenty billion, two hundred twenty-one million, one hundred thousand, twenty-one".