138535973 has 4 divisors (see below), whose sum is σ = 145827360. Its totient is φ = 131244588.

The previous prime is 138535963. The next prime is 138535997. The reversal of 138535973 is 379535831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138535973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138535913) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3645665 + ... + 3645702.

It is an arithmetic number, because the mean of its divisors is an integer number (36456840).

Almost surely, 2^138535973 is an apocalyptic number.

It is an amenable number.

138535973 is a deficient number, since it is larger than the sum of its proper divisors (7291387).

138535973 is an equidigital number, since it uses as much as digits as its factorization.

138535973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7291386.

The product of its digits is 340200, while the sum is 44.

The square root of 138535973 is about 11770.1305430314. The cubic root of 138535973 is about 517.4330755871.

The spelling of 138535973 in words is "one hundred thirty-eight million, five hundred thirty-five thousand, nine hundred seventy-three".