78320939 has 2 divisors, whose sum is σ = 78320940. Its totient is φ = 78320938.

The previous prime is 78320927. The next prime is 78320953. The reversal of 78320939 is 93902387.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78320939 is a prime.

It is a super-2 number, since 2×78320939² = 12268338971683442, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 78320896 and 78320905.

It is not a weakly prime, because it can be changed into another prime (78320959) 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 as a sum of consecutive naturals, namely, 39160469 + 39160470.

It is an arithmetic number, because the mean of its divisors is an integer number (39160470).

Almost surely, 2^78320939 is an apocalyptic number.

78320939 is a deficient number, since it is larger than the sum of its proper divisors (1).

78320939 is an equidigital number, since it uses as much as digits as its factorization.

78320939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 78320939 is about 8849.9118074702. The cubic root of 78320939 is about 427.8510760152.

The spelling of 78320939 in words is "seventy-eight million, three hundred twenty thousand, nine hundred thirty-nine".