101818021 has 2 divisors, whose sum is σ = 101818022. Its totient is φ = 101818020.

The previous prime is 101818019. The next prime is 101818037. The reversal of 101818021 is 120818101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83448225 + 18369796 = 9135^2 + 4286^2 .

It is a cyclic number.

It is not a de Polignac number, because 101818021 - 2¹ = 101818019 is a prime.

Together with 101818019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 101817983 and 101818001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101818001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50909010 + 50909011.

It is an arithmetic number, because the mean of its divisors is an integer number (50909011).

Almost surely, 2^101818021 is an apocalyptic number.

It is an amenable number.

101818021 is a deficient number, since it is larger than the sum of its proper divisors (1).

101818021 is an equidigital number, since it uses as much as digits as its factorization.

101818021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 22.

The square root of 101818021 is about 10090.4916133953. The cubic root of 101818021 is about 466.9548428137.

The spelling of 101818021 in words is "one hundred one million, eight hundred eighteen thousand, twenty-one".