21020102101 has 2 divisors, whose sum is σ = 21020102102. Its totient is φ = 21020102100.

The previous prime is 21020102093. The next prime is 21020102113. The reversal of 21020102101 is 10120102012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10671923025 + 10348179076 = 103305^2 + 101726^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020102101 - 2³ = 21020102093 is a prime.

It is a super-2 number, since 2×21020102101² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020105101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510051050 + 10510051051.

It is an arithmetic number, because the mean of its divisors is an integer number (10510051051).

Almost surely, 2^21020102101 is an apocalyptic number.

It is an amenable number.

21020102101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020102101 is an equidigital number, since it uses as much as digits as its factorization.

21020102101 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21020102101 its reverse (10120102012), we get a palindrome (31140204113).

The spelling of 21020102101 in words is "twenty-one billion, twenty million, one hundred two thousand, one hundred one".