78604781 has 2 divisors, whose sum is σ = 78604782. Its totient is φ = 78604780.

The previous prime is 78604733. The next prime is 78604789. The reversal of 78604781 is 18740687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76825225 + 1779556 = 8765^2 + 1334^2 .

It is a cyclic number.

It is not a de Polignac number, because 78604781 - 2¹⁸ = 78342637 is a prime.

It is a super-2 number, since 2×78604781² = 12357423192115922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78604789) 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, 39302390 + 39302391.

It is an arithmetic number, because the mean of its divisors is an integer number (39302391).

Almost surely, 2^78604781 is an apocalyptic number.

It is an amenable number.

78604781 is a deficient number, since it is larger than the sum of its proper divisors (1).

78604781 is an equidigital number, since it uses as much as digits as its factorization.

78604781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 75264, while the sum is 41.

The square root of 78604781 is about 8865.9337353716. The cubic root of 78604781 is about 428.3673095865.

The spelling of 78604781 in words is "seventy-eight million, six hundred four thousand, seven hundred eighty-one".