21210544013 has 2 divisors, whose sum is σ = 21210544014. Its totient is φ = 21210544012.

The previous prime is 21210543983. The next prime is 21210544093. The reversal of 21210544013 is 31044501212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20787295684 + 423248329 = 144178^2 + 20573^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210544013 - 2²² = 21206349709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21210544013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210544093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605272006 + 10605272007.

It is an arithmetic number, because the mean of its divisors is an integer number (10605272007).

Almost surely, 2^21210544013 is an apocalyptic number.

It is an amenable number.

21210544013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210544013 is an equidigital number, since it uses as much as digits as its factorization.

21210544013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 23.

The spelling of 21210544013 in words is "twenty-one billion, two hundred ten million, five hundred forty-four thousand, thirteen".