138948909 has 8 divisors (see below), whose sum is σ = 202107552. Its totient is φ = 84211440.

The previous prime is 138948893. The next prime is 138948941. The reversal of 138948909 is 909849831.

It is a happy number.

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

It is not a de Polignac number, because 138948909 - 2⁴ = 138948893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138948989) 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, 2105254 + ... + 2105319.

It is an arithmetic number, because the mean of its divisors is an integer number (25263444).

Almost surely, 2^138948909 is an apocalyptic number.

It is an amenable number.

138948909 is a deficient number, since it is larger than the sum of its proper divisors (63158643).

138948909 is a wasteful number, since it uses less digits than its factorization.

138948909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4210587.

The product of its (nonzero) digits is 559872, while the sum is 51.

The square root of 138948909 is about 11787.6591823822. The cubic root of 138948909 is about 517.9466721585.

The spelling of 138948909 in words is "one hundred thirty-eight million, nine hundred forty-eight thousand, nine hundred nine".