21013444313 has 2 divisors, whose sum is σ = 21013444314. Its totient is φ = 21013444312.

The previous prime is 21013444301. The next prime is 21013444351. The reversal of 21013444313 is 31344431012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20967908809 + 45535504 = 144803^2 + 6748^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21013444313 is a prime.

It is not a weakly prime, because it can be changed into another prime (21013444013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506722156 + 10506722157.

It is an arithmetic number, because the mean of its divisors is an integer number (10506722157).

Almost surely, 2^21013444313 is an apocalyptic number.

It is an amenable number.

21013444313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013444313 is an equidigital number, since it uses as much as digits as its factorization.

21013444313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 26.

Adding to 21013444313 its reverse (31344431012), we get a palindrome (52357875325).

The spelling of 21013444313 in words is "twenty-one billion, thirteen million, four hundred forty-four thousand, three hundred thirteen".