864778469 has 2 divisors, whose sum is σ = 864778470. Its totient is φ = 864778468.

The previous prime is 864778441. The next prime is 864778471. The reversal of 864778469 is 964877468.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 860718244 + 4060225 = 29338^2 + 2015^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-864778469 is a prime.

It is a super-2 number, since 2×864778469² = 1495683600891967922, which contains 22 as substring.

Together with 864778471, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (864778489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432389234 + 432389235.

It is an arithmetic number, because the mean of its divisors is an integer number (432389235).

Almost surely, 2^864778469 is an apocalyptic number.

It is an amenable number.

864778469 is a deficient number, since it is larger than the sum of its proper divisors (1).

864778469 is an equidigital number, since it uses as much as digits as its factorization.

864778469 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16257024, while the sum is 59.

The square root of 864778469 is about 29407.1159585567. The cubic root of 864778469 is about 952.7265968194.

The spelling of 864778469 in words is "eight hundred sixty-four million, seven hundred seventy-eight thousand, four hundred sixty-nine".