138828691 has 8 divisors (see below), whose sum is σ = 140304384. Its totient is φ = 137359560.

The previous prime is 138828689. The next prime is 138828719. The reversal of 138828691 is 196828831.

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 138828691 - 2¹ = 138828689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138828601) 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 in 7 ways as a sum of consecutive naturals, for example, 48790 + ... + 51556.

It is an arithmetic number, because the mean of its divisors is an integer number (17538048).

Almost surely, 2^138828691 is an apocalyptic number.

138828691 is a deficient number, since it is larger than the sum of its proper divisors (1475693).

138828691 is a wasteful number, since it uses less digits than its factorization.

138828691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3281.

The product of its digits is 165888, while the sum is 46.

The square root of 138828691 is about 11782.5587628494. The cubic root of 138828691 is about 517.7972539786.

The spelling of 138828691 in words is "one hundred thirty-eight million, eight hundred twenty-eight thousand, six hundred ninety-one".