138191911 has 8 divisors (see below), whose sum is σ = 162351504. Its totient is φ = 115965120.

The previous prime is 138191909. The next prime is 138191953. The reversal of 138191911 is 119191831.

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 138191911 - 2¹ = 138191909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138191111) 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, 483046 + ... + 483331.

It is an arithmetic number, because the mean of its divisors is an integer number (20293938).

Almost surely, 2^138191911 is an apocalyptic number.

138191911 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

138191911 is a deficient number, since it is larger than the sum of its proper divisors (24159593).

138191911 is a wasteful number, since it uses less digits than its factorization.

138191911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966401.

The product of its digits is 1944, while the sum is 34.

The square root of 138191911 is about 11755.5055612253. The cubic root of 138191911 is about 517.0043622826.

The spelling of 138191911 in words is "one hundred thirty-eight million, one hundred ninety-one thousand, nine hundred eleven".