138406775 has 72 divisors (see below), whose sum is σ = 205861824. Its totient is φ = 91852800.

The previous prime is 138406757. The next prime is 138406789. The reversal of 138406775 is 577604831.

It is not a de Polignac number, because 138406775 - 2⁸ = 138406519 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2944802 + ... + 2944848.

It is an arithmetic number, because the mean of its divisors is an integer number (2859192).

Almost surely, 2^138406775 is an apocalyptic number.

138406775 is a deficient number, since it is larger than the sum of its proper divisors (67455049).

138406775 is a wasteful number, since it uses less digits than its factorization.

138406775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 41.

The square root of 138406775 is about 11764.6408784969. The cubic root of 138406775 is about 517.2721736698.

The spelling of 138406775 in words is "one hundred thirty-eight million, four hundred six thousand, seven hundred seventy-five".