138628155 has 8 divisors (see below), whose sum is σ = 221805072. Its totient is φ = 73935008.

The previous prime is 138628151. The next prime is 138628163. The reversal of 138628155 is 551826831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138628155 - 2² = 138628151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138628151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4620924 + ... + 4620953.

It is an arithmetic number, because the mean of its divisors is an integer number (27725634).

Almost surely, 2^138628155 is an apocalyptic number.

138628155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138628155 is a deficient number, since it is larger than the sum of its proper divisors (83176917).

138628155 is an equidigital number, since it uses as much as digits as its factorization.

138628155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9241885.

The product of its digits is 57600, while the sum is 39.

The square root of 138628155 is about 11774.0458212120. The cubic root of 138628155 is about 517.5478170010.

The spelling of 138628155 in words is "one hundred thirty-eight million, six hundred twenty-eight thousand, one hundred fifty-five".