78625532681 has 2 divisors, whose sum is σ = 78625532682. Its totient is φ = 78625532680.

The previous prime is 78625532677. The next prime is 78625532693. The reversal of 78625532681 is 18623552687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78509238025 + 116294656 = 280195^2 + 10784^2 .

It is an emirp because it is prime and its reverse (18623552687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78625532681 - 2² = 78625532677 is a prime.

It is a super-2 number, since 2×78625532681² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78625532611) 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, 39312766340 + 39312766341.

It is an arithmetic number, because the mean of its divisors is an integer number (39312766341).

Almost surely, 2^78625532681 is an apocalyptic number.

It is an amenable number.

78625532681 is a deficient number, since it is larger than the sum of its proper divisors (1).

78625532681 is an equidigital number, since it uses as much as digits as its factorization.

78625532681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4838400, while the sum is 53.

The spelling of 78625532681 in words is "seventy-eight billion, six hundred twenty-five million, five hundred thirty-two thousand, six hundred eighty-one".