101816578021 has 2 divisors, whose sum is σ = 101816578022. Its totient is φ = 101816578020.

The previous prime is 101816578001. The next prime is 101816578063. The reversal of 101816578021 is 120875618101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58015948225 + 43800629796 = 240865^2 + 209286^2 .

It is a cyclic number.

It is not a de Polignac number, because 101816578021 - 2¹⁵ = 101816545253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101816578001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50908289010 + 50908289011.

It is an arithmetic number, because the mean of its divisors is an integer number (50908289011).

Almost surely, 2^101816578021 is an apocalyptic number.

It is an amenable number.

101816578021 is a deficient number, since it is larger than the sum of its proper divisors (1).

101816578021 is an equidigital number, since it uses as much as digits as its factorization.

101816578021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 40.

The spelling of 101816578021 in words is "one hundred one billion, eight hundred sixteen million, five hundred seventy-eight thousand, twenty-one".