7998338981 has 2 divisors, whose sum is σ = 7998338982. Its totient is φ = 7998338980.

The previous prime is 7998338977. The next prime is 7998338983. The reversal of 7998338981 is 1898338997.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4591282081 + 3407056900 = 67759^2 + 58370^2 .

It is a cyclic number.

It is not a de Polignac number, because 7998338981 - 2² = 7998338977 is a prime.

It is a super-2 number, since 2×7998338981² (a number of 21 digits) contains 22 as substring.

Together with 7998338983, 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 (7998338983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3999169490 + 3999169491.

It is an arithmetic number, because the mean of its divisors is an integer number (3999169491).

Almost surely, 2^7998338981 is an apocalyptic number.

It is an amenable number.

7998338981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7998338981 is an equidigital number, since it uses as much as digits as its factorization.

7998338981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23514624, while the sum is 65.

The square root of 7998338981 is about 89433.4332394771. The cubic root of 7998338981 is about 1999.8615721691.

The spelling of 7998338981 in words is "seven billion, nine hundred ninety-eight million, three hundred thirty-eight thousand, nine hundred eighty-one".