21102313 has 2 divisors, whose sum is σ = 21102314. Its totient is φ = 21102312.

The previous prime is 21102311. The next prime is 21102377. The reversal of 21102313 is 31320112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19430464 + 1671849 = 4408^2 + 1293^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102313 - 2¹ = 21102311 is a prime.

It is a super-2 number, since 2×21102313² = 890615227899938, which contains 22 as substring.

Together with 21102311, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21102293 and 21102302.

It is not a weakly prime, because it can be changed into another prime (21102311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551156 + 10551157.

It is an arithmetic number, because the mean of its divisors is an integer number (10551157).

Almost surely, 2^21102313 is an apocalyptic number.

It is an amenable number.

21102313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102313 is an equidigital number, since it uses as much as digits as its factorization.

21102313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21102313 is about 4593.7253944919. The cubic root of 21102313 is about 276.3397456205.

Adding to 21102313 its reverse (31320112), we get a palindrome (52422425).

The spelling of 21102313 in words is "twenty-one million, one hundred two thousand, three hundred thirteen".