101530021 has 2 divisors, whose sum is σ = 101530022. Its totient is φ = 101530020.

The previous prime is 101530019. The next prime is 101530133. The reversal of 101530021 is 120035101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66601921 + 34928100 = 8161^2 + 5910^2 .

It is a cyclic number.

It is not a de Polignac number, because 101530021 - 2¹ = 101530019 is a prime.

Together with 101530019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 101529983 and 101530010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101530621) 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, 50765010 + 50765011.

It is an arithmetic number, because the mean of its divisors is an integer number (50765011).

Almost surely, 2^101530021 is an apocalyptic number.

It is an amenable number.

101530021 is a deficient number, since it is larger than the sum of its proper divisors (1).

101530021 is an equidigital number, since it uses as much as digits as its factorization.

101530021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 101530021 is about 10076.2106468652. The cubic root of 101530021 is about 466.5141546412.

Adding to 101530021 its reverse (120035101), we get a palindrome (221565122).

The spelling of 101530021 in words is "one hundred one million, five hundred thirty thousand, twenty-one".