78443641 has 2 divisors, whose sum is σ = 78443642. Its totient is φ = 78443640.

The previous prime is 78443623. The next prime is 78443689. The reversal of 78443641 is 14634487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72318016 + 6125625 = 8504^2 + 2475^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78443641 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78443641.

It is not a weakly prime, because it can be changed into another prime (78443941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39221820 + 39221821.

It is an arithmetic number, because the mean of its divisors is an integer number (39221821).

Almost surely, 2^78443641 is an apocalyptic number.

It is an amenable number.

78443641 is a deficient number, since it is larger than the sum of its proper divisors (1).

78443641 is an equidigital number, since it uses as much as digits as its factorization.

78443641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 37.

The square root of 78443641 is about 8856.8414798956. The cubic root of 78443641 is about 428.0743913112.

The spelling of 78443641 in words is "seventy-eight million, four hundred forty-three thousand, six hundred forty-one".