138191643 has 8 divisors (see below), whose sum is σ = 204728400. Its totient is φ = 92127744.

The previous prime is 138191549. The next prime is 138191663. The reversal of 138191643 is 346191831.

138191643 is a `hidden beast` number, since 1 + 3 + 8 + 1 + 9 + 1 + 643 = 666.

It is not a de Polignac number, because 138191643 - 2¹² = 138187547 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 138191598 and 138191607.

It is not an unprimeable number, because it can be changed into a prime (138191663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2559078 + ... + 2559131.

It is an arithmetic number, because the mean of its divisors is an integer number (25591050).

Almost surely, 2^138191643 is an apocalyptic number.

138191643 is a deficient number, since it is larger than the sum of its proper divisors (66536757).

138191643 is an equidigital number, since it uses as much as digits as its factorization.

138191643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5118218 (or 5118212 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 138191643 is about 11755.4941623056. The cubic root of 138191643 is about 517.0040280680.

The spelling of 138191643 in words is "one hundred thirty-eight million, one hundred ninety-one thousand, six hundred forty-three".