138481645 has 4 divisors (see below), whose sum is σ = 166177980. Its totient is φ = 110785312.

The previous prime is 138481631. The next prime is 138481661. The reversal of 138481645 is 546184831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 546184831 = 22717 ⋅24043.

It can be written as a sum of positive squares in 2 ways, for example, as 32844361 + 105637284 = 5731^2 + 10278^2 .

It is a cyclic number.

It is not a de Polignac number, because 138481645 - 2¹³ = 138473453 is a prime.

It is a super-3 number, since 3×138481645³ (a number of 25 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138481598 and 138481607.

It is a congruent 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, 13848160 + ... + 13848169.

It is an arithmetic number, because the mean of its divisors is an integer number (41544495).

Almost surely, 2^138481645 is an apocalyptic number.

It is an amenable number.

138481645 is a deficient number, since it is larger than the sum of its proper divisors (27696335).

138481645 is an equidigital number, since it uses as much as digits as its factorization.

138481645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27696334.

The product of its digits is 92160, while the sum is 40.

The square root of 138481645 is about 11767.8224408766. The cubic root of 138481645 is about 517.3654282245.

The spelling of 138481645 in words is "one hundred thirty-eight million, four hundred eighty-one thousand, six hundred forty-five".