78005321 has 2 divisors, whose sum is σ = 78005322. Its totient is φ = 78005320.

The previous prime is 78005303. The next prime is 78005359. The reversal of 78005321 is 12350087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50965321 + 27040000 = 7139^2 + 5200^2 .

It is an emirp because it is prime and its reverse (12350087) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78005321 is a prime.

It is not a weakly prime, because it can be changed into another prime (78005381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39002660 + 39002661.

It is an arithmetic number, because the mean of its divisors is an integer number (39002661).

Almost surely, 2^78005321 is an apocalyptic number.

It is an amenable number.

78005321 is a deficient number, since it is larger than the sum of its proper divisors (1).

78005321 is an equidigital number, since it uses as much as digits as its factorization.

78005321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 78005321 is about 8832.0621034954. The cubic root of 78005321 is about 427.2755836826.

The spelling of 78005321 in words is "seventy-eight million, five thousand, three hundred twenty-one".