201620101021 has 2 divisors, whose sum is σ = 201620101022. Its totient is φ = 201620101020.

The previous prime is 201620101019. The next prime is 201620101049. The reversal of 201620101021 is 120101026102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107987160996 + 93632940025 = 328614^2 + 305995^2 .

It is a cyclic number.

It is not a de Polignac number, because 201620101021 - 2¹ = 201620101019 is a prime.

Together with 201620101019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 201620100986 and 201620101004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201620101051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100810050510 + 100810050511.

It is an arithmetic number, because the mean of its divisors is an integer number (100810050511).

Almost surely, 2^201620101021 is an apocalyptic number.

It is an amenable number.

201620101021 is a deficient number, since it is larger than the sum of its proper divisors (1).

201620101021 is an equidigital number, since it uses as much as digits as its factorization.

201620101021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 201620101021 its reverse (120101026102), we get a palindrome (321721127123).

The spelling of 201620101021 in words is "two hundred one billion, six hundred twenty million, one hundred one thousand, twenty-one".