78817641 has 16 divisors (see below), whose sum is σ = 121344384. Its totient is φ = 44573184.

The previous prime is 78817639. The next prime is 78817699. The reversal of 78817641 is 14671887.

It is a happy number.

It is not a de Polignac number, because 78817641 - 2¹ = 78817639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78817593 and 78817602.

It is not an unprimeable number, because it can be changed into a prime (78817441) 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 15 ways as a sum of consecutive naturals, for example, 17310 + ... + 21383.

It is an arithmetic number, because the mean of its divisors is an integer number (7584024).

Almost surely, 2^78817641 is an apocalyptic number.

It is an amenable number.

78817641 is a deficient number, since it is larger than the sum of its proper divisors (42526743).

78817641 is a wasteful number, since it uses less digits than its factorization.

78817641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38800.

The product of its digits is 75264, while the sum is 42.

The square root of 78817641 is about 8877.9299952185. The cubic root of 78817641 is about 428.7536307977.

The spelling of 78817641 in words is "seventy-eight million, eight hundred seventeen thousand, six hundred forty-one".