78164393 has 2 divisors, whose sum is σ = 78164394. Its totient is φ = 78164392.

The previous prime is 78164381. The next prime is 78164413. The reversal of 78164393 is 39346187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78092569 + 71824 = 8837^2 + 268^2 .

It is a cyclic number.

It is not a de Polignac number, because 78164393 - 2⁴ = 78164377 is a prime.

It is a super-2 number, since 2×78164393² = 12219344666116898, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78164393.

It is not a weakly prime, because it can be changed into another prime (78164293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39082196 + 39082197.

It is an arithmetic number, because the mean of its divisors is an integer number (39082197).

Almost surely, 2^78164393 is an apocalyptic number.

It is an amenable number.

78164393 is a deficient number, since it is larger than the sum of its proper divisors (1).

78164393 is an equidigital number, since it uses as much as digits as its factorization.

78164393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 41.

The square root of 78164393 is about 8841.0628885898. The cubic root of 78164393 is about 427.5658264172.

The spelling of 78164393 in words is "seventy-eight million, one hundred sixty-four thousand, three hundred ninety-three".