78320117 has 2 divisors, whose sum is σ = 78320118. Its totient is φ = 78320116.

The previous prime is 78320113. The next prime is 78320131. The reversal of 78320117 is 71102387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71132356 + 7187761 = 8434^2 + 2681^2 .

It is an emirp because it is prime and its reverse (71102387) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78320117 - 2² = 78320113 is a prime.

It is a super-2 number, since 2×78320117² = 12268081453787378, which contains 22 as substring.

It is a Chen prime.

It is equal to p_4577123 and since 78320117 and 4577123 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78320117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78320111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39160058 + 39160059.

It is an arithmetic number, because the mean of its divisors is an integer number (39160059).

Almost surely, 2^78320117 is an apocalyptic number.

It is an amenable number.

78320117 is a deficient number, since it is larger than the sum of its proper divisors (1).

78320117 is an equidigital number, since it uses as much as digits as its factorization.

78320117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 78320117 is about 8849.8653662076. The cubic root of 78320117 is about 427.8495792047.

The spelling of 78320117 in words is "seventy-eight million, three hundred twenty thousand, one hundred seventeen".