101921 has 2 divisors, whose sum is σ = 101922. Its totient is φ = 101920.

The previous prime is 101917. The next prime is 101929. The reversal of 101921 is 129101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55696 + 46225 = 236^2 + 215^2 .

It is a cyclic number.

It is not a de Polignac number, because 101921 - 2² = 101917 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 101896 and 101905.

It is not a weakly prime, because it can be changed into another prime (101929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50960 + 50961.

It is an arithmetic number, because the mean of its divisors is an integer number (50961).

2¹⁰¹⁹²¹ is an apocalyptic number.

It is an amenable number.

101921 is a deficient number, since it is larger than the sum of its proper divisors (1).

101921 is an equidigital number, since it uses as much as digits as its factorization.

101921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 101921 is about 319.2506851990. The cubic root of 101921 is about 46.7112216200.

The spelling of 101921 in words is "one hundred one thousand, nine hundred twenty-one".