20001322981 has 2 divisors, whose sum is σ = 20001322982. Its totient is φ = 20001322980.

The previous prime is 20001322963. The next prime is 20001323053. The reversal of 20001322981 is 18922310002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11613510756 + 8387812225 = 107766^2 + 91585^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001322981 - 2²³ = 19992934373 is a prime.

It is a super-2 number, since 2×20001322981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001322921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000661490 + 10000661491.

It is an arithmetic number, because the mean of its divisors is an integer number (10000661491).

Almost surely, 2^20001322981 is an apocalyptic number.

It is an amenable number.

20001322981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001322981 is an equidigital number, since it uses as much as digits as its factorization.

20001322981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

Adding to 20001322981 its reverse (18922310002), we get a palindrome (38923632983).

The spelling of 20001322981 in words is "twenty billion, one million, three hundred twenty-two thousand, nine hundred eighty-one".