78399229 has 2 divisors, whose sum is σ = 78399230. Its totient is φ = 78399228.

The previous prime is 78399193. The next prime is 78399241. The reversal of 78399229 is 92299387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78322500 + 76729 = 8850^2 + 277^2 .

It is a cyclic number.

It is not a de Polignac number, because 78399229 - 2⁹ = 78398717 is a prime.

It is a super-2 number, since 2×78399229² = 12292878215588882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78399329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39199614 + 39199615.

It is an arithmetic number, because the mean of its divisors is an integer number (39199615).

Almost surely, 2^78399229 is an apocalyptic number.

It is an amenable number.

78399229 is a deficient number, since it is larger than the sum of its proper divisors (1).

78399229 is an equidigital number, since it uses as much as digits as its factorization.

78399229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 49.

The square root of 78399229 is about 8854.3339105774. Note that the first 3 decimals coincide. The cubic root of 78399229 is about 427.9935892276.

The spelling of 78399229 in words is "seventy-eight million, three hundred ninety-nine thousand, two hundred twenty-nine".