2002217981 has 2 divisors, whose sum is σ = 2002217982. Its totient is φ = 2002217980.

The previous prime is 2002217957. The next prime is 2002217983. The reversal of 2002217981 is 1897122002.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1966922500 + 35295481 = 44350^2 + 5941^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2002217981 is a prime.

It is a super-2 number, since 2×2002217981² = 8017753686879432722, which contains 22 as substring.

Together with 2002217983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2002217983) 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, 1001108990 + 1001108991.

It is an arithmetic number, because the mean of its divisors is an integer number (1001108991).

Almost surely, 2^2002217981 is an apocalyptic number.

It is an amenable number.

2002217981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2002217981 is an equidigital number, since it uses as much as digits as its factorization.

2002217981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 2002217981 is about 44746.1504601234. The cubic root of 2002217981 is about 1260.3866246563.

Adding to 2002217981 its reverse (1897122002), we get a palindrome (3899339983).

The spelling of 2002217981 in words is "two billion, two million, two hundred seventeen thousand, nine hundred eighty-one".