78823321 has 2 divisors, whose sum is σ = 78823322. Its totient is φ = 78823320.

The previous prime is 78823319. The next prime is 78823333. The reversal of 78823321 is 12332887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74563225 + 4260096 = 8635^2 + 2064^2 .

It is a cyclic number.

It is not a de Polignac number, because 78823321 - 2¹ = 78823319 is a prime.

Together with 78823319, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (78823391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39411660 + 39411661.

It is an arithmetic number, because the mean of its divisors is an integer number (39411661).

Almost surely, 2^78823321 is an apocalyptic number.

It is an amenable number.

78823321 is a deficient number, since it is larger than the sum of its proper divisors (1).

78823321 is an equidigital number, since it uses as much as digits as its factorization.

78823321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 34.

The square root of 78823321 is about 8878.2498838454. The cubic root of 78823321 is about 428.7639299392.

The spelling of 78823321 in words is "seventy-eight million, eight hundred twenty-three thousand, three hundred twenty-one".