21012016817683 has 2 divisors, whose sum is σ = 21012016817684. Its totient is φ = 21012016817682.

The previous prime is 21012016817681. The next prime is 21012016817699. The reversal of 21012016817683 is 38671861021012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21012016817683 - 2¹ = 21012016817681 is a prime.

It is a super-2 number, since 2×21012016817683² (a number of 27 digits) contains 22 as substring.

Together with 21012016817681, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21012016817681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506008408841 + 10506008408842.

It is an arithmetic number, because the mean of its divisors is an integer number (10506008408842).

Almost surely, 2^{21012016817683} is an apocalyptic number.

21012016817683 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012016817683 is an equidigital number, since it uses as much as digits as its factorization.

21012016817683 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 193536, while the sum is 46.

Adding to 21012016817683 its reverse (38671861021012), we get a palindrome (59683877838695).

The spelling of 21012016817683 in words is "twenty-one trillion, twelve billion, sixteen million, eight hundred seventeen thousand, six hundred eighty-three".