7120111981 has 2 divisors, whose sum is σ = 7120111982. Its totient is φ = 7120111980.

The previous prime is 7120111963. The next prime is 7120111991. The reversal of 7120111981 is 1891110217.

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., 5786036356 + 1334075625 = 76066^2 + 36525^2 .

It is an emirp because it is prime and its reverse (1891110217) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7120111981 - 2⁵ = 7120111949 is a prime.

It is a super-2 number, since 2×7120111981² (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 (7120111991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3560055990 + 3560055991.

It is an arithmetic number, because the mean of its divisors is an integer number (3560055991).

Almost surely, 2^7120111981 is an apocalyptic number.

It is an amenable number.

7120111981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7120111981 is an equidigital number, since it uses as much as digits as its factorization.

7120111981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 31.

The square root of 7120111981 is about 84380.7559873695. The cubic root of 7120111981 is about 1923.8104287939.

The spelling of 7120111981 in words is "seven billion, one hundred twenty million, one hundred eleven thousand, nine hundred eighty-one".