20001002221 has 2 divisors, whose sum is σ = 20001002222. Its totient is φ = 20001002220.

The previous prime is 20001002201. The next prime is 20001002227. The reversal of 20001002221 is 12220010002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16638162121 + 3362840100 = 128989^2 + 57990^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001002221 - 2¹³ = 20000994029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20001002198 and 20001002207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001002227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000501110 + 10000501111.

It is an arithmetic number, because the mean of its divisors is an integer number (10000501111).

Almost surely, 2^20001002221 is an apocalyptic number.

It is an amenable number.

20001002221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001002221 is an equidigital number, since it uses as much as digits as its factorization.

20001002221 is an evil number, because the sum of its binary digits is even.

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

Adding to 20001002221 its reverse (12220010002), we get a palindrome (32221012223).

The spelling of 20001002221 in words is "twenty billion, one million, two thousand, two hundred twenty-one".