678444769 has 2 divisors, whose sum is σ = 678444770. Its totient is φ = 678444768.

The previous prime is 678444757. The next prime is 678444773. The reversal of 678444769 is 967444876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 546998544 + 131446225 = 23388^2 + 11465^2 .

It is a cyclic number.

It is not a de Polignac number, because 678444769 - 2¹⁵ = 678412001 is a prime.

It is a super-2 number, since 2×678444769² = 920574609166926722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (678444709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339222384 + 339222385.

It is an arithmetic number, because the mean of its divisors is an integer number (339222385).

Almost surely, 2^678444769 is an apocalyptic number.

It is an amenable number.

678444769 is a deficient number, since it is larger than the sum of its proper divisors (1).

678444769 is an equidigital number, since it uses as much as digits as its factorization.

678444769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8128512, while the sum is 55.

The square root of 678444769 is about 26046.9723576465. The cubic root of 678444769 is about 878.6950221198.

It can be divided in two parts, 67 and 8444769, that added together give a square (8444836 = 2906²).

The spelling of 678444769 in words is "six hundred seventy-eight million, four hundred forty-four thousand, seven hundred sixty-nine".