78836641 has 9 divisors (see below), whose sum is σ = 85492659. Its totient is φ = 72665736.

The previous prime is 78836629. The next prime is 78836669. The reversal of 78836641 is 14663887.

The square root of 78836641 is 8879.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 11662225 + 67174416 = 3415^2 + 8196^2 .

It is not a de Polignac number, because 78836641 - 2⁹ = 78836129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78836671) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 115086 + ... + 115768.

Almost surely, 2^78836641 is an apocalyptic number.

78836641 is the 8879-th square number.

78836641 is the 4440-th centered octagonal number.

It is an amenable number.

78836641 is a deficient number, since it is larger than the sum of its proper divisors (6656018).

78836641 is an frugal number, since it uses more digits than its factorization.

78836641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1392 (or 696 counting only the distinct ones).

The product of its digits is 193536, while the sum is 43.

The cubic root of 78836641 is about 428.7880802110.

The spelling of 78836641 in words is "seventy-eight million, eight hundred thirty-six thousand, six hundred forty-one".