138831305 has 8 divisors (see below), whose sum is σ = 170472192. Its totient is φ = 108481968.

The previous prime is 138831293. The next prime is 138831313. The reversal of 138831305 is 503138831.

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 138831305 - 2¹⁶ = 138765769 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 322649 + ... + 323078.

It is an arithmetic number, because the mean of its divisors is an integer number (21309024).

Almost surely, 2^138831305 is an apocalyptic number.

It is an amenable number.

138831305 is a deficient number, since it is larger than the sum of its proper divisors (31640887).

138831305 is an equidigital number, since it uses as much as digits as its factorization.

138831305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645775.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 138831305 is about 11782.6696889966. The cubic root of 138831305 is about 517.8005038197.

The spelling of 138831305 in words is "one hundred thirty-eight million, eight hundred thirty-one thousand, three hundred five".