20002981 has 2 divisors, whose sum is σ = 20002982. Its totient is φ = 20002980.

The previous prime is 20002979. The next prime is 20003003. The reversal of 20002981 is 18920002.

It is an a-pointer prime, because the next prime (20003003) can be obtained adding 20002981 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11329956 + 8673025 = 3366^2 + 2945^2 .

It is a cyclic number.

It is not a de Polignac number, because 20002981 - 2¹ = 20002979 is a prime.

It is a super-2 number, since 2×20002981² = 800238497772722, which contains 22 as substring.

Together with 20002979, 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 (20002951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10001490 + 10001491.

It is an arithmetic number, because the mean of its divisors is an integer number (10001491).

Almost surely, 2^20002981 is an apocalyptic number.

It is an amenable number.

20002981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20002981 is an equidigital number, since it uses as much as digits as its factorization.

20002981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 20002981 is about 4472.4692285135. The cubic root of 20002981 is about 271.4552471210.

Adding to 20002981 its reverse (18920002), we get a palindrome (38922983).

The spelling of 20002981 in words is "twenty million, two thousand, nine hundred eighty-one".