21011111983 has 2 divisors, whose sum is σ = 21011111984. Its totient is φ = 21011111982.

The previous prime is 21011111977. The next prime is 21011112011. The reversal of 21011111983 is 38911111012.

It is an a-pointer prime, because the next prime (21011112011) can be obtained adding 21011111983 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21011111983 - 2¹⁷ = 21010980911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011111963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505555991 + 10505555992.

It is an arithmetic number, because the mean of its divisors is an integer number (10505555992).

Almost surely, 2^21011111983 is an apocalyptic number.

21011111983 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011111983 is an equidigital number, since it uses as much as digits as its factorization.

21011111983 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 28.

Adding to 21011111983 its reverse (38911111012), we get a palindrome (59922222995).

The spelling of 21011111983 in words is "twenty-one billion, eleven million, one hundred eleven thousand, nine hundred eighty-three".