1338591691 has 4 divisors (see below), whose sum is σ = 1363848192. Its totient is φ = 1313335192.

The previous prime is 1338591671. The next prime is 1338591701. The reversal of 1338591691 is 1961958331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1961958331 = 317 ⋅6189143.

It is a cyclic number.

It is not a de Polignac number, because 1338591691 - 2⁵ = 1338591659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1338591671) 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 3 ways as a sum of consecutive naturals, for example, 12628171 + ... + 12628276.

It is an arithmetic number, because the mean of its divisors is an integer number (340962048).

Almost surely, 2^1338591691 is an apocalyptic number.

1338591691 is a deficient number, since it is larger than the sum of its proper divisors (25256501).

1338591691 is an equidigital number, since it uses as much as digits as its factorization.

1338591691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25256500.

The product of its digits is 174960, while the sum is 46.

The square root of 1338591691 is about 36586.7693435756. The cubic root of 1338591691 is about 1102.0874112566.

The spelling of 1338591691 in words is "one billion, three hundred thirty-eight million, five hundred ninety-one thousand, six hundred ninety-one".