78089749 has 4 divisors (see below), whose sum is σ = 78107436. Its totient is φ = 78072064.

The previous prime is 78089747. The next prime is 78089771. The reversal of 78089749 is 94798087.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 39463524 + 38626225 = 6282^2 + 6215^2 .

It is a cyclic number.

It is not a de Polignac number, because 78089749 - 2¹ = 78089747 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78089696 and 78089705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78089747) 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 in 3 ways as a sum of consecutive naturals, for example, 3927 + ... + 13099.

It is an arithmetic number, because the mean of its divisors is an integer number (19526859).

Almost surely, 2^78089749 is an apocalyptic number.

It is an amenable number.

78089749 is a deficient number, since it is larger than the sum of its proper divisors (17687).

78089749 is an equidigital number, since it uses as much as digits as its factorization.

78089749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17686.

The product of its (nonzero) digits is 1016064, while the sum is 52.

The square root of 78089749 is about 8836.8404421490. The cubic root of 78089749 is about 427.4296800766.

The spelling of 78089749 in words is "seventy-eight million, eighty-nine thousand, seven hundred forty-nine".