78486869 has 2 divisors, whose sum is σ = 78486870. Its totient is φ = 78486868.

The previous prime is 78486817. The next prime is 78486887. The reversal of 78486869 is 96868487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52852900 + 25633969 = 7270^2 + 5063^2 .

It is an emirp because it is prime and its reverse (96868487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78486869 - 2⁸ = 78486613 is a prime.

It is a super-2 number, since 2×78486869² = 12320377210846322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78486469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39243434 + 39243435.

It is an arithmetic number, because the mean of its divisors is an integer number (39243435).

Almost surely, 2^78486869 is an apocalyptic number.

It is an amenable number.

78486869 is a deficient number, since it is larger than the sum of its proper divisors (1).

78486869 is an equidigital number, since it uses as much as digits as its factorization.

78486869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4644864, while the sum is 56.

The square root of 78486869 is about 8859.2815171435. The cubic root of 78486869 is about 428.1530099706.

The spelling of 78486869 in words is "seventy-eight million, four hundred eighty-six thousand, eight hundred sixty-nine".