21326101 has 2 divisors, whose sum is σ = 21326102. Its totient is φ = 21326100.

The previous prime is 21326099. The next prime is 21326111. The reversal of 21326101 is 10162312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12320100 + 9006001 = 3510^2 + 3001^2 .

It is a cyclic number.

It is not a de Polignac number, because 21326101 - 2¹ = 21326099 is a prime.

Together with 21326099, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21326111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10663050 + 10663051.

It is an arithmetic number, because the mean of its divisors is an integer number (10663051).

Almost surely, 2^21326101 is an apocalyptic number.

It is an amenable number.

21326101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21326101 is an equidigital number, since it uses as much as digits as its factorization.

21326101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21326101 is about 4618.0191641006. The cubic root of 21326101 is about 277.3131648237.

Adding to 21326101 its reverse (10162312), we get a palindrome (31488413).

The spelling of 21326101 in words is "twenty-one million, three hundred twenty-six thousand, one hundred one".