138643997 has 8 divisors (see below), whose sum is σ = 146446080. Its totient is φ = 131050080.

The previous prime is 138643991. The next prime is 138644017. The reversal of 138643997 is 799346831.

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 138643997 - 2¹⁴ = 138627613 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 (138643991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50672 + ... + 53337.

It is an arithmetic number, because the mean of its divisors is an integer number (18305760).

Almost surely, 2^138643997 is an apocalyptic number.

It is an amenable number.

138643997 is a deficient number, since it is larger than the sum of its proper divisors (7802083).

138643997 is a wasteful number, since it uses less digits than its factorization.

138643997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104083.

The product of its digits is 979776, while the sum is 50.

The square root of 138643997 is about 11774.7185528997. The cubic root of 138643997 is about 517.5675308420.

The spelling of 138643997 in words is "one hundred thirty-eight million, six hundred forty-three thousand, nine hundred ninety-seven".