78764681 has 2 divisors, whose sum is σ = 78764682. Its totient is φ = 78764680.

The previous prime is 78764641. The next prime is 78764711. The reversal of 78764681 is 18646787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67980025 + 10784656 = 8245^2 + 3284^2 .

It is a cyclic number.

It is not a de Polignac number, because 78764681 - 2⁶ = 78764617 is a prime.

It is a super-2 number, since 2×78764681² = 12407749946063522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78764611) 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, 39382340 + 39382341.

It is an arithmetic number, because the mean of its divisors is an integer number (39382341).

Almost surely, 2^78764681 is an apocalyptic number.

It is an amenable number.

78764681 is a deficient number, since it is larger than the sum of its proper divisors (1).

78764681 is an equidigital number, since it uses as much as digits as its factorization.

78764681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 451584, while the sum is 47.

The square root of 78764681 is about 8874.9468167421. The cubic root of 78764681 is about 428.6575783586.

The spelling of 78764681 in words is "seventy-eight million, seven hundred sixty-four thousand, six hundred eighty-one".