78819331 has 2 divisors, whose sum is σ = 78819332. Its totient is φ = 78819330.

The previous prime is 78819313. The next prime is 78819337. The reversal of 78819331 is 13391887.

Together with previous prime (78819313) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78819331 - 2¹⁹ = 78295043 is a prime.

It is a super-2 number, since 2×78819331² = 12424973878575122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78819337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39409665 + 39409666.

It is an arithmetic number, because the mean of its divisors is an integer number (39409666).

Almost surely, 2^78819331 is an apocalyptic number.

78819331 is a deficient number, since it is larger than the sum of its proper divisors (1).

78819331 is an equidigital number, since it uses as much as digits as its factorization.

78819331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 40.

The square root of 78819331 is about 8878.0251745532. The cubic root of 78819331 is about 428.7566952066.

The spelling of 78819331 in words is "seventy-eight million, eight hundred nineteen thousand, three hundred thirty-one".