21100220101 has 2 divisors, whose sum is σ = 21100220102. Its totient is φ = 21100220100.

The previous prime is 21100220069. The next prime is 21100220111. The reversal of 21100220101 is 10102200112.

It is an a-pointer prime, because the next prime (21100220111) can be obtained adding 21100220101 to its sum of digits (10).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11324152225 + 9776067876 = 106415^2 + 98874^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100220101 - 2⁵ = 21100220069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100220111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550110050 + 10550110051.

It is an arithmetic number, because the mean of its divisors is an integer number (10550110051).

Almost surely, 2^21100220101 is an apocalyptic number.

It is an amenable number.

21100220101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100220101 is an equidigital number, since it uses as much as digits as its factorization.

21100220101 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 21100220101 its reverse (10102200112), we get a palindrome (31202420213).

The spelling of 21100220101 in words is "twenty-one billion, one hundred million, two hundred twenty thousand, one hundred one".