21021020983663 has 2 divisors, whose sum is σ = 21021020983664. Its totient is φ = 21021020983662.

The previous prime is 21021020983639. The next prime is 21021020983667. The reversal of 21021020983663 is 36638902012012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021020983663 is a prime.

It is a super-2 number, since 2×21021020983663² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021020983667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510510491831 + 10510510491832.

It is an arithmetic number, because the mean of its divisors is an integer number (10510510491832).

Almost surely, 2^{21021020983663} is an apocalyptic number.

21021020983663 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021020983663 is an equidigital number, since it uses as much as digits as its factorization.

21021020983663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 43.

Adding to 21021020983663 its reverse (36638902012012), we get a palindrome (57659922995675).

The spelling of 21021020983663 in words is "twenty-one trillion, twenty-one billion, twenty million, nine hundred eighty-three thousand, six hundred sixty-three".