138445657 has 4 divisors (see below), whose sum is σ = 158223616. Its totient is φ = 118667700.

The previous prime is 138445639. The next prime is 138445667. The reversal of 138445657 is 756544831.

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 not a de Polignac number, because 138445657 - 2¹¹ = 138443609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138445627) 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, 9888969 + ... + 9888982.

It is an arithmetic number, because the mean of its divisors is an integer number (39555904).

Almost surely, 2^138445657 is an apocalyptic number.

It is an amenable number.

138445657 is a deficient number, since it is larger than the sum of its proper divisors (19777959).

138445657 is an equidigital number, since it uses as much as digits as its factorization.

138445657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19777958.

The product of its digits is 403200, while the sum is 43.

The square root of 138445657 is about 11766.2932565868. The cubic root of 138445657 is about 517.3206074587.

The spelling of 138445657 in words is "one hundred thirty-eight million, four hundred forty-five thousand, six hundred fifty-seven".