20221020001981 has 2 divisors, whose sum is σ = 20221020001982. Its totient is φ = 20221020001980.

The previous prime is 20221020001943. The next prime is 20221020002021. The reversal of 20221020001981 is 18910002012202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11246022613081 + 8974997388900 = 3353509^2 + 2995830^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20221020001981 is a prime.

It is a super-2 number, since 2×20221020001981² (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 (20221020001081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10110510000990 + 10110510000991.

It is an arithmetic number, because the mean of its divisors is an integer number (10110510000991).

Almost surely, 2^{20221020001981} is an apocalyptic number.

It is an amenable number.

20221020001981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20221020001981 is an equidigital number, since it uses as much as digits as its factorization.

20221020001981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 28.

The spelling of 20221020001981 in words is "twenty trillion, two hundred twenty-one billion, twenty million, one thousand, nine hundred eighty-one".