1398688769 has 2 divisors, whose sum is σ = 1398688770. Its totient is φ = 1398688768.

The previous prime is 1398688679. The next prime is 1398688799. The reversal of 1398688769 is 9678868931.

Together with previous prime (1398688679) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 993069169 + 405619600 = 31513^2 + 20140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1398688769 is a prime.

It is a super-2 number, since 2×1398688769² = 3912660545053470722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1398688799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 699344384 + 699344385.

It is an arithmetic number, because the mean of its divisors is an integer number (699344385).

Almost surely, 2^1398688769 is an apocalyptic number.

It is an amenable number.

1398688769 is a deficient number, since it is larger than the sum of its proper divisors (1).

1398688769 is an equidigital number, since it uses as much as digits as its factorization.

1398688769 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31352832, while the sum is 65.

The square root of 1398688769 is about 37399.0477017798. The cubic root of 1398688769 is about 1118.3395806983.

The spelling of 1398688769 in words is "one billion, three hundred ninety-eight million, six hundred eighty-eight thousand, seven hundred sixty-nine".