21311202113 has 2 divisors, whose sum is σ = 21311202114. Its totient is φ = 21311202112.

The previous prime is 21311202103. The next prime is 21311202149. The reversal of 21311202113 is 31120211312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20488200769 + 823001344 = 143137^2 + 28688^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311202113 - 2¹² = 21311198017 is a prime.

It is a super-2 number, since 2×21311202113² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21311202091 and 21311202100.

It is not a weakly prime, because it can be changed into another prime (21311202103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655601056 + 10655601057.

It is an arithmetic number, because the mean of its divisors is an integer number (10655601057).

Almost surely, 2^21311202113 is an apocalyptic number.

It is an amenable number.

21311202113 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311202113 is an equidigital number, since it uses as much as digits as its factorization.

21311202113 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21311202113 its reverse (31120211312), we get a palindrome (52431413425).

The spelling of 21311202113 in words is "twenty-one billion, three hundred eleven million, two hundred two thousand, one hundred thirteen".