7725691081 has 2 divisors, whose sum is σ = 7725691082. Its totient is φ = 7725691080.

The previous prime is 7725691073. The next prime is 7725691093. The reversal of 7725691081 is 1801965277.

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., 6471398025 + 1254293056 = 80445^2 + 35416^2 .

It is a cyclic number.

It is not a de Polignac number, because 7725691081 - 2³ = 7725691073 is a prime.

It is a super-2 number, since 2×7725691081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7725691681) 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, 3862845540 + 3862845541.

It is an arithmetic number, because the mean of its divisors is an integer number (3862845541).

Almost surely, 2^7725691081 is an apocalyptic number.

It is an amenable number.

7725691081 is a deficient number, since it is larger than the sum of its proper divisors (1).

7725691081 is an equidigital number, since it uses as much as digits as its factorization.

7725691081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 211680, while the sum is 46.

The square root of 7725691081 is about 87895.9104907617. The cubic root of 7725691081 is about 1976.8745610500.

The spelling of 7725691081 in words is "seven billion, seven hundred twenty-five million, six hundred ninety-one thousand, eighty-one".