21012020220101 has 2 divisors, whose sum is σ = 21012020220102. Its totient is φ = 21012020220100.

The previous prime is 21012020220071. The next prime is 21012020220203. The reversal of 21012020220101 is 10102202021012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17029405288900 + 3982614931201 = 4126670^2 + 1995649^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012020220101 - 2¹⁴ = 21012020203717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012020225101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506010110050 + 10506010110051.

It is an arithmetic number, because the mean of its divisors is an integer number (10506010110051).

Almost surely, 2^{21012020220101} is an apocalyptic number.

It is an amenable number.

21012020220101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012020220101 is an equidigital number, since it uses as much as digits as its factorization.

21012020220101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21012020220101 its reverse (10102202021012), we get a palindrome (31114222241113).

The spelling of 21012020220101 in words is "twenty-one trillion, twelve billion, twenty million, two hundred twenty thousand, one hundred one".