20010011221 has 2 divisors, whose sum is σ = 20010011222. Its totient is φ = 20010011220.

The previous prime is 20010011209. The next prime is 20010011227. The reversal of 20010011221 is 12211001002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13283715025 + 6726296196 = 115255^2 + 82014^2 .

It is a cyclic number.

It is not a de Polignac number, because 20010011221 - 2¹⁹ = 20009486933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20010011198 and 20010011207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20010011227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005005610 + 10005005611.

It is an arithmetic number, because the mean of its divisors is an integer number (10005005611).

Almost surely, 2^20010011221 is an apocalyptic number.

It is an amenable number.

20010011221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20010011221 is an equidigital number, since it uses as much as digits as its factorization.

20010011221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20010011221 its reverse (12211001002), we get a palindrome (32221012223).

The spelling of 20010011221 in words is "twenty billion, ten million, eleven thousand, two hundred twenty-one".