7768115521 has 2 divisors, whose sum is σ = 7768115522. Its totient is φ = 7768115520.

The previous prime is 7768115461. The next prime is 7768115527. The reversal of 7768115521 is 1255118677.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5107103296 + 2661012225 = 71464^2 + 51585^2 .

It is an emirp because it is prime and its reverse (1255118677) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7768115521 - 2⁹ = 7768115009 is a prime.

It is a super-2 number, since 2×7768115521² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7768115527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3884057760 + 3884057761.

It is an arithmetic number, because the mean of its divisors is an integer number (3884057761).

Almost surely, 2^7768115521 is an apocalyptic number.

It is an amenable number.

7768115521 is a deficient number, since it is larger than the sum of its proper divisors (1).

7768115521 is an equidigital number, since it uses as much as digits as its factorization.

7768115521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 117600, while the sum is 43.

The square root of 7768115521 is about 88136.9134982613. The cubic root of 7768115521 is about 1980.4865247466.

The spelling of 7768115521 in words is "seven billion, seven hundred sixty-eight million, one hundred fifteen thousand, five hundred twenty-one".