7711981 has 2 divisors, whose sum is σ = 7711982. Its totient is φ = 7711980.

The previous prime is 7711943. The next prime is 7711987. The reversal of 7711981 is 1891177.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7452900 + 259081 = 2730^2 + 509^2 .

It is a cyclic number.

It is not a de Polignac number, because 7711981 - 2⁹ = 7711469 is a prime.

It is a super-2 number, since 2×7711981² = 118949301888722, which contains 22 as substring.

7711981 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7711987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3855990 + 3855991.

It is an arithmetic number, because the mean of its divisors is an integer number (3855991).

Almost surely, 2^7711981 is an apocalyptic number.

It is an amenable number.

7711981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7711981 is an equidigital number, since it uses as much as digits as its factorization.

7711981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 34.

The square root of 7711981 is about 2777.0453723337. The cubic root of 7711981 is about 197.5704475493.

The spelling of 7711981 in words is "seven million, seven hundred eleven thousand, nine hundred eighty-one".