102101210021 has 2 divisors, whose sum is σ = 102101210022. Its totient is φ = 102101210020.

The previous prime is 102101210011. The next prime is 102101210089. The reversal of 102101210021 is 120012101201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59958868225 + 42142341796 = 244865^2 + 205286^2 .

It is a cyclic number.

It is not a de Polignac number, because 102101210021 - 2¹⁸ = 102100947877 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 102101209984 and 102101210011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102101210011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51050605010 + 51050605011.

It is an arithmetic number, because the mean of its divisors is an integer number (51050605011).

Almost surely, 2^102101210021 is an apocalyptic number.

It is an amenable number.

102101210021 is a deficient number, since it is larger than the sum of its proper divisors (1).

102101210021 is an equidigital number, since it uses as much as digits as its factorization.

102101210021 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 11.

Adding to 102101210021 its reverse (120012101201), we get a palindrome (222113311222).

The spelling of 102101210021 in words is "one hundred two billion, one hundred one million, two hundred ten thousand, twenty-one".