78117073 has 2 divisors, whose sum is σ = 78117074. Its totient is φ = 78117072.

The previous prime is 78117043. The next prime is 78117079. The reversal of 78117073 is 37071187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75047569 + 3069504 = 8663^2 + 1752^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78117073 is a prime.

It is a super-2 number, since 2×78117073² = 12204554188174658, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78117079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39058536 + 39058537.

It is an arithmetic number, because the mean of its divisors is an integer number (39058537).

Almost surely, 2^78117073 is an apocalyptic number.

It is an amenable number.

78117073 is a deficient number, since it is larger than the sum of its proper divisors (1).

78117073 is an equidigital number, since it uses as much as digits as its factorization.

78117073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8232, while the sum is 34.

The square root of 78117073 is about 8838.3863346201. The cubic root of 78117073 is about 427.4795275355.

It can be divided in two parts, 7811 and 7073, that added together give a square (14884 = 122²).

The spelling of 78117073 in words is "seventy-eight million, one hundred seventeen thousand, seventy-three".