78346399 has 2 divisors, whose sum is σ = 78346400. Its totient is φ = 78346398.

The previous prime is 78346379. The next prime is 78346507. The reversal of 78346399 is 99364387.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78346399 - 2¹¹ = 78344351 is a prime.

It is a super-2 number, since 2×78346399² = 12276316472534402, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78346369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39173199 + 39173200.

It is an arithmetic number, because the mean of its divisors is an integer number (39173200).

Almost surely, 2^78346399 is an apocalyptic number.

78346399 is a deficient number, since it is larger than the sum of its proper divisors (1).

78346399 is an equidigital number, since it uses as much as digits as its factorization.

78346399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 49.

The square root of 78346399 is about 8851.3501230038. The cubic root of 78346399 is about 427.8974318957.

The spelling of 78346399 in words is "seventy-eight million, three hundred forty-six thousand, three hundred ninety-nine".