7728322981 has 2 divisors, whose sum is σ = 7728322982. Its totient is φ = 7728322980.

The previous prime is 7728322937. The next prime is 7728323027. The reversal of 7728322981 is 1892238277.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7718501025 + 9821956 = 87855^2 + 3134^2 .

It is a cyclic number.

It is not a de Polignac number, because 7728322981 - 2⁷ = 7728322853 is a prime.

It is a super-2 number, since 2×7728322981² (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 (7728322081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3864161490 + 3864161491.

It is an arithmetic number, because the mean of its divisors is an integer number (3864161491).

Almost surely, 2^7728322981 is an apocalyptic number.

It is an amenable number.

7728322981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7728322981 is an equidigital number, since it uses as much as digits as its factorization.

7728322981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 677376, while the sum is 49.

The square root of 7728322981 is about 87910.8809021955. The cubic root of 7728322981 is about 1977.0990218949.

The spelling of 7728322981 in words is "seven billion, seven hundred twenty-eight million, three hundred twenty-two thousand, nine hundred eighty-one".