21012021983 has 2 divisors, whose sum is σ = 21012021984. Its totient is φ = 21012021982.

The previous prime is 21012021973. The next prime is 21012022027. The reversal of 21012021983 is 38912021012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21012021983 - 2¹⁶ = 21011956447 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012021923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506010991 + 10506010992.

It is an arithmetic number, because the mean of its divisors is an integer number (10506010992).

Almost surely, 2^21012021983 is an apocalyptic number.

21012021983 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012021983 is an equidigital number, since it uses as much as digits as its factorization.

21012021983 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 29.

Adding to 21012021983 its reverse (38912021012), we get a palindrome (59924042995).

The spelling of 21012021983 in words is "twenty-one billion, twelve million, twenty-one thousand, nine hundred eighty-three".