138993841 has 6 divisors (see below), whose sum is σ = 161686770. Its totient is φ = 119137536.

The previous prime is 138993817. The next prime is 138993847. The reversal of 138993841 is 148399831.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 110691441 + 28302400 = 10521^2 + 5320^2 .

It is not a de Polignac number, because 138993841 - 2¹⁵ = 138961073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 138993791 and 138993800.

It is not an unprimeable number, because it can be changed into a prime (138993847) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1418256 + ... + 1418353.

It is an arithmetic number, because the mean of its divisors is an integer number (26947795).

Almost surely, 2^138993841 is an apocalyptic number.

It is an amenable number.

138993841 is a deficient number, since it is larger than the sum of its proper divisors (22692929).

138993841 is an equidigital number, since it uses as much as digits as its factorization.

138993841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2836623 (or 2836616 counting only the distinct ones).

The product of its digits is 186624, while the sum is 46.

The square root of 138993841 is about 11789.5649198772. The cubic root of 138993841 is about 518.0024957270.

The spelling of 138993841 in words is "one hundred thirty-eight million, nine hundred ninety-three thousand, eight hundred forty-one".