20220001981 has 2 divisors, whose sum is σ = 20220001982. Its totient is φ = 20220001980.

The previous prime is 20220001979. The next prime is 20220002003. The reversal of 20220001981 is 18910002202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19918805956 + 301196025 = 141134^2 + 17355^2 .

It is a cyclic number.

It is not a de Polignac number, because 20220001981 - 2¹ = 20220001979 is a prime.

It is a super-3 number, since 3×20220001981³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 20220001979, 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 (20220001961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10110000990 + 10110000991.

It is an arithmetic number, because the mean of its divisors is an integer number (10110000991).

Almost surely, 2^20220001981 is an apocalyptic number.

It is an amenable number.

20220001981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20220001981 is an equidigital number, since it uses as much as digits as its factorization.

20220001981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The spelling of 20220001981 in words is "twenty billion, two hundred twenty million, one thousand, nine hundred eighty-one".