138505547 has 4 divisors (see below), whose sum is σ = 138531456. Its totient is φ = 138479640.

The previous prime is 138505513. The next prime is 138505559. The reversal of 138505547 is 745505831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138505547 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138505547.

It is not an unprimeable number, because it can be changed into a prime (138505847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1643 + ... + 16724.

It is an arithmetic number, because the mean of its divisors is an integer number (34632864).

Almost surely, 2^138505547 is an apocalyptic number.

138505547 is a deficient number, since it is larger than the sum of its proper divisors (25909).

138505547 is an equidigital number, since it uses as much as digits as its factorization.

138505547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25908.

The product of its (nonzero) digits is 84000, while the sum is 38.

The square root of 138505547 is about 11768.8379630276. The cubic root of 138505547 is about 517.3951923545.

The spelling of 138505547 in words is "one hundred thirty-eight million, five hundred five thousand, five hundred forty-seven".