78488681 has 2 divisors, whose sum is σ = 78488682. Its totient is φ = 78488680.

The previous prime is 78488671. The next prime is 78488689. The reversal of 78488681 is 18688487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39488656 + 39000025 = 6284^2 + 6245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78488681 is a prime.

It is a super-2 number, since 2×78488681² = 12320946090239522, which 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 (78488689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39244340 + 39244341.

It is an arithmetic number, because the mean of its divisors is an integer number (39244341).

Almost surely, 2^78488681 is an apocalyptic number.

It is an amenable number.

78488681 is a deficient number, since it is larger than the sum of its proper divisors (1).

78488681 is an equidigital number, since it uses as much as digits as its factorization.

78488681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 688128, while the sum is 50.

The square root of 78488681 is about 8859.3837821826. The cubic root of 78488681 is about 428.1563048202.

The spelling of 78488681 in words is "seventy-eight million, four hundred eighty-eight thousand, six hundred eighty-one".