138188465 has 4 divisors (see below), whose sum is σ = 165826164. Its totient is φ = 110550768.

The previous prime is 138188441. The next prime is 138188473. The reversal of 138188465 is 564881831.

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: 564881831 = 17 ⋅33228343.

It can be written as a sum of positive squares in 2 ways, for example, as 52940176 + 85248289 = 7276^2 + 9233^2 .

It is a cyclic number.

It is not a de Polignac number, because 138188465 - 2¹⁴ = 138172081 is a prime.

It is a super-3 number, since 3×138188465³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13818842 + ... + 13818851.

It is an arithmetic number, because the mean of its divisors is an integer number (41456541).

Almost surely, 2^138188465 is an apocalyptic number.

It is an amenable number.

138188465 is a deficient number, since it is larger than the sum of its proper divisors (27637699).

138188465 is an equidigital number, since it uses as much as digits as its factorization.

138188465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27637698.

The product of its digits is 184320, while the sum is 44.

The square root of 138188465 is about 11755.3589906902. The cubic root of 138188465 is about 517.0000648487. Note that the first 4 decimals are identical.

The spelling of 138188465 in words is "one hundred thirty-eight million, one hundred eighty-eight thousand, four hundred sixty-five".