138684555 has 40 divisors (see below), whose sum is σ = 263241792. Its totient is φ = 69610752.

The previous prime is 138684551. The next prime is 138684563. The reversal of 138684555 is 555486831.

138684555 is a `hidden beast` number, since 1 + 38 + 68 + 4 + 555 = 666.

It is not a de Polignac number, because 138684555 - 2² = 138684551 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 138684555.

It is not an unprimeable number, because it can be changed into a prime (138684551) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3187 + ... + 16956.

Almost surely, 2^138684555 is an apocalyptic number.

138684555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138684555 is a deficient number, since it is larger than the sum of its proper divisors (124557237).

138684555 is a wasteful number, since it uses less digits than its factorization.

138684555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20177 (or 20168 counting only the distinct ones).

The product of its digits is 576000, while the sum is 45.

The square root of 138684555 is about 11776.4406761975. The cubic root of 138684555 is about 517.6179945182.

The spelling of 138684555 in words is "one hundred thirty-eight million, six hundred eighty-four thousand, five hundred fifty-five".