78238393 has 2 divisors, whose sum is σ = 78238394. Its totient is φ = 78238392.

The previous prime is 78238351. The next prime is 78238397. The reversal of 78238393 is 39383287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41113744 + 37124649 = 6412^2 + 6093^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78238393 is a prime.

It is a super-2 number, since 2×78238393² = 12242492278444898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78238397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39119196 + 39119197.

It is an arithmetic number, because the mean of its divisors is an integer number (39119197).

Almost surely, 2^78238393 is an apocalyptic number.

It is an amenable number.

78238393 is a deficient number, since it is larger than the sum of its proper divisors (1).

78238393 is an equidigital number, since it uses as much as digits as its factorization.

78238393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 43.

The square root of 78238393 is about 8845.2469157169. The cubic root of 78238393 is about 427.7007126080.

The spelling of 78238393 in words is "seventy-eight million, two hundred thirty-eight thousand, three hundred ninety-three".