78578237 has 2 divisors, whose sum is σ = 78578238. Its totient is φ = 78578236.

The previous prime is 78578221. The next prime is 78578239. The reversal of 78578237 is 73287587.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77246521 + 1331716 = 8789^2 + 1154^2 .

It is a cyclic number.

It is not a de Polignac number, because 78578237 - 2⁴ = 78578221 is a prime.

Together with 78578239, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 78578191 and 78578200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78578239) 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, 39289118 + 39289119.

It is an arithmetic number, because the mean of its divisors is an integer number (39289119).

Almost surely, 2^78578237 is an apocalyptic number.

It is an amenable number.

78578237 is a deficient number, since it is larger than the sum of its proper divisors (1).

78578237 is an equidigital number, since it uses as much as digits as its factorization.

78578237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 658560, while the sum is 47.

The square root of 78578237 is about 8864.4366431263. The cubic root of 78578237 is about 428.3190857937.

The spelling of 78578237 in words is "seventy-eight million, five hundred seventy-eight thousand, two hundred thirty-seven".