78181673 has 2 divisors, whose sum is σ = 78181674. Its totient is φ = 78181672.

The previous prime is 78181661. The next prime is 78181679. The reversal of 78181673 is 37618187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72046144 + 6135529 = 8488^2 + 2477^2 .

It is a cyclic number.

It is not a de Polignac number, because 78181673 - 2⁸ = 78181417 is a prime.

It is a super-4 number, since 4×78181673⁴ (a number of 33 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 78181673.

It is not a weakly prime, because it can be changed into another prime (78181679) 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, 39090836 + 39090837.

It is an arithmetic number, because the mean of its divisors is an integer number (39090837).

Almost surely, 2^78181673 is an apocalyptic number.

It is an amenable number.

78181673 is a deficient number, since it is larger than the sum of its proper divisors (1).

78181673 is an equidigital number, since it uses as much as digits as its factorization.

78181673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 41.

The square root of 78181673 is about 8842.0400926483. The cubic root of 78181673 is about 427.5973317818.

The spelling of 78181673 in words is "seventy-eight million, one hundred eighty-one thousand, six hundred seventy-three".