78965681 has 4 divisors (see below), whose sum is σ = 79064100. Its totient is φ = 78867264.

The previous prime is 78965669. The next prime is 78965683. The reversal of 78965681 is 18656987.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 53875600 + 25090081 = 7340^2 + 5009^2 .

It is a cyclic number.

It is not a de Polignac number, because 78965681 - 2⁶ = 78965617 is a prime.

It is a super-2 number, since 2×78965681² = 12471157551587522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78965683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47996 + ... + 49613.

It is an arithmetic number, because the mean of its divisors is an integer number (19766025).

Almost surely, 2^78965681 is an apocalyptic number.

It is an amenable number.

78965681 is a deficient number, since it is larger than the sum of its proper divisors (98419).

78965681 is an equidigital number, since it uses as much as digits as its factorization.

78965681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98418.

The product of its digits is 725760, while the sum is 50.

The square root of 78965681 is about 8886.2636130153. The cubic root of 78965681 is about 429.0218997990.

The spelling of 78965681 in words is "seventy-eight million, nine hundred sixty-five thousand, six hundred eighty-one".