78485681 has 2 divisors, whose sum is σ = 78485682. Its totient is φ = 78485680.

The previous prime is 78485653. The next prime is 78485741. The reversal of 78485681 is 18658487.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77704225 + 781456 = 8815^2 + 884^2 .

It is a cyclic number.

It is not a de Polignac number, because 78485681 - 2¹⁰ = 78484657 is a prime.

It is a super-2 number, since 2×78485681² = 12320004244067522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78485611) 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, 39242840 + 39242841.

It is an arithmetic number, because the mean of its divisors is an integer number (39242841).

Almost surely, 2^78485681 is an apocalyptic number.

It is an amenable number.

78485681 is a deficient number, since it is larger than the sum of its proper divisors (1).

78485681 is an equidigital number, since it uses as much as digits as its factorization.

78485681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 430080, while the sum is 47.

The square root of 78485681 is about 8859.2144685632. The cubic root of 78485681 is about 428.1508497436.

The spelling of 78485681 in words is "seventy-eight million, four hundred eighty-five thousand, six hundred eighty-one".