138506377 has 4 divisors (see below), whose sum is σ = 139436100. Its totient is φ = 137576656.

The previous prime is 138506369. The next prime is 138506383. The reversal of 138506377 is 773605831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 773605831 = 487 ⋅1588513.

It can be written as a sum of positive squares in 2 ways, for example, as 61136761 + 77369616 = 7819^2 + 8796^2 .

It is a cyclic number.

It is not a de Polignac number, because 138506377 - 2³ = 138506369 is a prime.

It is a super-2 number, since 2×138506377² = 38368032939332258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138506317) 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, 464638 + ... + 464935.

It is an arithmetic number, because the mean of its divisors is an integer number (34859025).

Almost surely, 2^138506377 is an apocalyptic number.

It is an amenable number.

138506377 is a deficient number, since it is larger than the sum of its proper divisors (929723).

138506377 is an equidigital number, since it uses as much as digits as its factorization.

138506377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 929722.

The product of its (nonzero) digits is 105840, while the sum is 40.

The square root of 138506377 is about 11768.8732255896. The cubic root of 138506377 is about 517.3962258562.

The spelling of 138506377 in words is "one hundred thirty-eight million, five hundred six thousand, three hundred seventy-seven".