138608819 has 4 divisors (see below), whose sum is σ = 145904040. Its totient is φ = 131313600.

The previous prime is 138608807. The next prime is 138608839. The reversal of 138608819 is 918806831.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 138608819 - 2²⁴ = 121831603 is a prime.

It is a super-2 number, since 2×138608819² = 38424809409149522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 138608819.

It is not an unprimeable number, because it can be changed into a prime (138608839) 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, 3647582 + ... + 3647619.

It is an arithmetic number, because the mean of its divisors is an integer number (36476010).

Almost surely, 2^138608819 is an apocalyptic number.

138608819 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

138608819 is a deficient number, since it is larger than the sum of its proper divisors (7295221).

138608819 is an equidigital number, since it uses as much as digits as its factorization.

138608819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7295220.

The product of its (nonzero) digits is 82944, while the sum is 44.

The square root of 138608819 is about 11773.2246644664. The cubic root of 138608819 is about 517.5237531786.

The spelling of 138608819 in words is "one hundred thirty-eight million, six hundred eight thousand, eight hundred nineteen".