138406943 has 4 divisors (see below), whose sum is σ = 138468408. Its totient is φ = 138345480.

The previous prime is 138406921. The next prime is 138406949. The reversal of 138406943 is 349604831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138406943 - 2¹⁰ = 138405919 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138406897 and 138406906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138406949) 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, 27221 + ... + 31902.

It is an arithmetic number, because the mean of its divisors is an integer number (34617102).

Almost surely, 2^138406943 is an apocalyptic number.

138406943 is a deficient number, since it is larger than the sum of its proper divisors (61465).

138406943 is an equidigital number, since it uses as much as digits as its factorization.

138406943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61464.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 138406943 is about 11764.6480185342. The cubic root of 138406943 is about 517.2723829603.

The spelling of 138406943 in words is "one hundred thirty-eight million, four hundred six thousand, nine hundred forty-three".