138691441 has 8 divisors (see below), whose sum is σ = 158672384. Its totient is φ = 118752480.

The previous prime is 138691439. The next prime is 138691453. The reversal of 138691441 is 144196831.

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

It is not a de Polignac number, because 138691441 - 2¹ = 138691439 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138691441.

It is not an unprimeable number, because it can be changed into a prime (138691481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3060 + ... + 16933.

It is an arithmetic number, because the mean of its divisors is an integer number (19834048).

Almost surely, 2^138691441 is an apocalyptic number.

It is an amenable number.

138691441 is a deficient number, since it is larger than the sum of its proper divisors (19980943).

138691441 is an equidigital number, since it uses as much as digits as its factorization.

138691441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20991.

The product of its digits is 20736, while the sum is 37.

The square root of 138691441 is about 11776.7330359485. The cubic root of 138691441 is about 517.6265613422.

The spelling of 138691441 in words is "one hundred thirty-eight million, six hundred ninety-one thousand, four hundred forty-one".