101021 has 2 divisors, whose sum is σ = 101022. Its totient is φ = 101020.

The previous prime is 101009. The next prime is 101027. The reversal of 101021 is 120101.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55225 + 45796 = 235^2 + 214^2 .

It is a cyclic number.

It is not a de Polignac number, because 101021 - 2⁶ = 100957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 100996 and 101014.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50510 + 50511.

It is an arithmetic number, because the mean of its divisors is an integer number (50511).

2¹⁰¹⁰²¹ is an apocalyptic number.

It is an amenable number.

101021 is a deficient number, since it is larger than the sum of its proper divisors (1).

101021 is an equidigital number, since it uses as much as digits as its factorization.

101021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2, while the sum is 5.

The square root of 101021 is about 317.8380090549. The cubic root of 101021 is about 46.5733224847.

Adding to 101021 its reverse (120101), we get a palindrome (221122).

Multiplying 101021 by its reverse (120101), we get a palindrome (12132723121).

The spelling of 101021 in words is "one hundred one thousand, twenty-one", and thus it is an iban number.