1368639989 has 8 divisors (see below), whose sum is σ = 1392566040. Its totient is φ = 1344854016.

The previous prime is 1368639973. The next prime is 1368640019. The reversal of 1368639989 is 9899368631.

It can be written as a sum of positive squares in 4 ways, for example, as 377019889 + 991620100 = 19417^2 + 31490^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1368639989 - 2⁴ = 1368639973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1368639919) 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 in 7 ways as a sum of consecutive naturals, for example, 15212 + ... + 54485.

It is an arithmetic number, because the mean of its divisors is an integer number (174070755).

Almost surely, 2^1368639989 is an apocalyptic number.

It is an amenable number.

1368639989 is a deficient number, since it is larger than the sum of its proper divisors (23926051).

1368639989 is an equidigital number, since it uses as much as digits as its factorization.

1368639989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70039.

The product of its digits is 15116544, while the sum is 62.

The square root of 1368639989 is about 36995.1346666018. The cubic root of 1368639989 is about 1110.2729056001.

The spelling of 1368639989 in words is "one billion, three hundred sixty-eight million, six hundred thirty-nine thousand, nine hundred eighty-nine".