138400655 has 36 divisors (see below), whose sum is σ = 188362920. Its totient is φ = 97332480.

The previous prime is 138400651. The next prime is 138400657. The reversal of 138400655 is 556004831.

It is a happy number.

It is not a de Polignac number, because 138400655 - 2² = 138400651 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138400651) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 1949270 + ... + 1949340.

Almost surely, 2^138400655 is an apocalyptic number.

138400655 is a deficient number, since it is larger than the sum of its proper divisors (49962265).

138400655 is an equidigital number, since it uses as much as digits as its factorization.

138400655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 112 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 138400655 is about 11764.3807741844. The cubic root of 138400655 is about 517.2645493986.

The spelling of 138400655 in words is "one hundred thirty-eight million, four hundred thousand, six hundred fifty-five".