102120220021 has 2 divisors, whose sum is σ = 102120220022. Its totient is φ = 102120220020.

The previous prime is 102120220019. The next prime is 102120220093. The reversal of 102120220021 is 120022021201.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 92363719396 + 9756500625 = 303914^2 + 98775^2 .

It is a cyclic number.

It is not a de Polignac number, because 102120220021 - 2¹ = 102120220019 is a prime.

Together with 102120220019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 102120219983 and 102120220010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102120220921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51060110010 + 51060110011.

It is an arithmetic number, because the mean of its divisors is an integer number (51060110011).

Almost surely, 2^102120220021 is an apocalyptic number.

It is an amenable number.

102120220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

102120220021 is an equidigital number, since it uses as much as digits as its factorization.

102120220021 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 13.

Adding to 102120220021 its reverse (120022021201), we get a palindrome (222142241222).

The spelling of 102120220021 in words is "one hundred two billion, one hundred twenty million, two hundred twenty thousand, twenty-one".