138780655 has 32 divisors (see below), whose sum is σ = 190794240. Its totient is φ = 96059520.

The previous prime is 138780559. The next prime is 138780671. The reversal of 138780655 is 556087831.

It is not a de Polignac number, because 138780655 - 2⁷ = 138780527 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 126660 + ... + 127750.

It is an arithmetic number, because the mean of its divisors is an integer number (5962320).

Almost surely, 2^138780655 is an apocalyptic number.

138780655 is a deficient number, since it is larger than the sum of its proper divisors (52013585).

138780655 is a wasteful number, since it uses less digits than its factorization.

138780655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1231.

The product of its (nonzero) digits is 201600, while the sum is 43.

The square root of 138780655 is about 11780.5201498066. The cubic root of 138780655 is about 517.7375262235.

The spelling of 138780655 in words is "one hundred thirty-eight million, seven hundred eighty thousand, six hundred fifty-five".