7987525661 has 2 divisors, whose sum is σ = 7987525662. Its totient is φ = 7987525660.

The previous prime is 7987525649. The next prime is 7987525699. The reversal of 7987525661 is 1665257897.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6388005625 + 1599520036 = 79925^2 + 39994^2 .

It is a cyclic number.

It is not a de Polignac number, because 7987525661 - 2³⁰ = 6913783837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7987525597 and 7987525606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7987522661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3993762830 + 3993762831.

It is an arithmetic number, because the mean of its divisors is an integer number (3993762831).

Almost surely, 2^7987525661 is an apocalyptic number.

It is an amenable number.

7987525661 is a deficient number, since it is larger than the sum of its proper divisors (1).

7987525661 is an equidigital number, since it uses as much as digits as its factorization.

7987525661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6350400, while the sum is 56.

The square root of 7987525661 is about 89372.9582200343. The cubic root of 7987525661 is about 1998.9599309720.

The spelling of 7987525661 in words is "seven billion, nine hundred eighty-seven million, five hundred twenty-five thousand, six hundred sixty-one".