20203321981 has 2 divisors, whose sum is σ = 20203321982. Its totient is φ = 20203321980.

The previous prime is 20203321979. The next prime is 20203321993. The reversal of 20203321981 is 18912330202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20180759481 + 22562500 = 142059^2 + 4750^2 .

It is a cyclic number.

It is not a de Polignac number, because 20203321981 - 2¹ = 20203321979 is a prime.

It is a super-2 number, since 2×20203321981² (a number of 21 digits) contains 22 as substring.

Together with 20203321979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20203321921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10101660990 + 10101660991.

It is an arithmetic number, because the mean of its divisors is an integer number (10101660991).

Almost surely, 2^20203321981 is an apocalyptic number.

It is an amenable number.

20203321981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20203321981 is an equidigital number, since it uses as much as digits as its factorization.

20203321981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 31.

The spelling of 20203321981 in words is "twenty billion, two hundred three million, three hundred twenty-one thousand, nine hundred eighty-one".