78689845 has 8 divisors (see below), whose sum is σ = 101691576. Its totient is φ = 58109376.

The previous prime is 78689827. The next prime is 78689851. The reversal of 78689845 is 54898687.

It can be written as a sum of positive squares in 4 ways, for example, as 2686321 + 76003524 = 1639^2 + 8718^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78689845 - 2⁹ = 78689333 is a prime.

It is a super-2 number, since 2×78689845² = 12384183412248050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 605242 + ... + 605371.

It is an arithmetic number, because the mean of its divisors is an integer number (12711447).

Almost surely, 2^78689845 is an apocalyptic number.

It is an amenable number.

78689845 is a deficient number, since it is larger than the sum of its proper divisors (23001731).

78689845 is a wasteful number, since it uses less digits than its factorization.

78689845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1210631.

The product of its digits is 3870720, while the sum is 55.

The square root of 78689845 is about 8870.7296768642. The cubic root of 78689845 is about 428.5217764435.

The spelling of 78689845 in words is "seventy-eight million, six hundred eighty-nine thousand, eight hundred forty-five".