21210003675617 has 2 divisors, whose sum is σ = 21210003675618. Its totient is φ = 21210003675616.

The previous prime is 21210003675611. The next prime is 21210003675677. The reversal of 21210003675617 is 71657630001212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21175790144656 + 34213530961 = 4601716^2 + 184969^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210003675617 - 2³² = 21205708708321 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210003675611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605001837808 + 10605001837809.

It is an arithmetic number, because the mean of its divisors is an integer number (10605001837809).

Almost surely, 2^{21210003675617} is an apocalyptic number.

It is an amenable number.

21210003675617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210003675617 is an equidigital number, since it uses as much as digits as its factorization.

21210003675617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 105840, while the sum is 41.

Adding to 21210003675617 its reverse (71657630001212), we get a palindrome (92867633676829).

The spelling of 21210003675617 in words is "twenty-one trillion, two hundred ten billion, three million, six hundred seventy-five thousand, six hundred seventeen".