138365775 has 72 divisors (see below), whose sum is σ = 259577136. Its totient is φ = 70387200.

The previous prime is 138365761. The next prime is 138365779. The reversal of 138365775 is 577563831.

It is not a de Polignac number, because 138365775 - 2¹² = 138361679 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 138365775.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138365779) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 488784 + ... + 489066.

It is an arithmetic number, because the mean of its divisors is an integer number (3605238).

Almost surely, 2^138365775 is an apocalyptic number.

138365775 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138365775 is a deficient number, since it is larger than the sum of its proper divisors (121211361).

138365775 is a wasteful number, since it uses less digits than its factorization.

138365775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 385 counting only the distinct ones).

The product of its digits is 529200, while the sum is 45.

The square root of 138365775 is about 11762.8982398047. The cubic root of 138365775 is about 517.2210917445.

The spelling of 138365775 in words is "one hundred thirty-eight million, three hundred sixty-five thousand, seven hundred seventy-five".