7863687521 has 2 divisors, whose sum is σ = 7863687522. Its totient is φ = 7863687520.

The previous prime is 7863687463. The next prime is 7863687581. The reversal of 7863687521 is 1257863687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6648119296 + 1215568225 = 81536^2 + 34865^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7863687521 is a prime.

It is a super-2 number, since 2×7863687521² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7863687581) 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, 3931843760 + 3931843761.

It is an arithmetic number, because the mean of its divisors is an integer number (3931843761).

Almost surely, 2^7863687521 is an apocalyptic number.

It is an amenable number.

7863687521 is a deficient number, since it is larger than the sum of its proper divisors (1).

7863687521 is an equidigital number, since it uses as much as digits as its factorization.

7863687521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3386880, while the sum is 53.

The square root of 7863687521 is about 88677.4352414412. The cubic root of 7863687521 is about 1988.5754913106.

The spelling of 7863687521 in words is "seven billion, eight hundred sixty-three million, six hundred eighty-seven thousand, five hundred twenty-one".