21301613 has 2 divisors, whose sum is σ = 21301614. Its totient is φ = 21301612.

The previous prime is 21301589. The next prime is 21301691. The reversal of 21301613 is 31610312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16540489 + 4761124 = 4067^2 + 2182^2 .

It is a cyclic number.

It is not a de Polignac number, because 21301613 - 2⁶ = 21301549 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21301591 and 21301600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21391613) 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, 10650806 + 10650807.

It is an arithmetic number, because the mean of its divisors is an integer number (10650807).

Almost surely, 2^21301613 is an apocalyptic number.

It is an amenable number.

21301613 is a deficient number, since it is larger than the sum of its proper divisors (1).

21301613 is an equidigital number, since it uses as much as digits as its factorization.

21301613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 21301613 is about 4615.3670493255. The cubic root of 21301613 is about 277.2069812373.

Adding to 21301613 its reverse (31610312), we get a palindrome (52911925).

The spelling of 21301613 in words is "twenty-one million, three hundred one thousand, six hundred thirteen".