138120657 has 4 divisors (see below), whose sum is σ = 184160880. Its totient is φ = 92080436.

The previous prime is 138120637. The next prime is 138120679. The reversal of 138120657 is 756021831.

138120657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 138120657 - 2¹⁰ = 138119633 is a prime.

It is a super-2 number, since 2×138120657² = 38154631780223298, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138120607) 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, 23020107 + ... + 23020112.

It is an arithmetic number, because the mean of its divisors is an integer number (46040220).

Almost surely, 2^138120657 is an apocalyptic number.

It is an amenable number.

138120657 is a deficient number, since it is larger than the sum of its proper divisors (46040223).

138120657 is an equidigital number, since it uses as much as digits as its factorization.

138120657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46040222.

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 138120657 is about 11752.4745053967. The cubic root of 138120657 is about 516.9154883828.

The spelling of 138120657 in words is "one hundred thirty-eight million, one hundred twenty thousand, six hundred fifty-seven".