78229913 has 2 divisors, whose sum is σ = 78229914. Its totient is φ = 78229912.

The previous prime is 78229909. The next prime is 78229933. The reversal of 78229913 is 31992287.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58186384 + 20043529 = 7628^2 + 4477^2 .

It is a cyclic number.

It is not a de Polignac number, because 78229913 - 2² = 78229909 is a prime.

It is a super-2 number, since 2×78229913² = 12239838575975138, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (78229933) 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, 39114956 + 39114957.

It is an arithmetic number, because the mean of its divisors is an integer number (39114957).

Almost surely, 2^78229913 is an apocalyptic number.

It is an amenable number.

78229913 is a deficient number, since it is larger than the sum of its proper divisors (1).

78229913 is an equidigital number, since it uses as much as digits as its factorization.

78229913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 41.

The square root of 78229913 is about 8844.7675492350. The cubic root of 78229913 is about 427.6852596957.

The spelling of 78229913 in words is "seventy-eight million, two hundred twenty-nine thousand, nine hundred thirteen".