138511523 has 4 divisors (see below), whose sum is σ = 139393920. Its totient is φ = 137629128.

The previous prime is 138511519. The next prime is 138511553. The reversal of 138511523 is 325115831.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 325115831 = 1721 ⋅188911.

It is a cyclic number.

It is not a de Polignac number, because 138511523 - 2² = 138511519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138511553) 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, 440963 + ... + 441276.

It is an arithmetic number, because the mean of its divisors is an integer number (34848480).

Almost surely, 2^138511523 is an apocalyptic number.

138511523 is a deficient number, since it is larger than the sum of its proper divisors (882397).

138511523 is an equidigital number, since it uses as much as digits as its factorization.

138511523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 882396.

The product of its digits is 3600, while the sum is 29.

The square root of 138511523 is about 11769.0918511158. The cubic root of 138511523 is about 517.4026334746.

The spelling of 138511523 in words is "one hundred thirty-eight million, five hundred eleven thousand, five hundred twenty-three".