138635947 has 4 divisors (see below), whose sum is σ = 141585696. Its totient is φ = 135686200.

The previous prime is 138635911. The next prime is 138635957. The reversal of 138635947 is 749536831.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138635947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138635897 and 138635906.

It is not an unprimeable number, because it can be changed into a prime (138635957) 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 3 ways as a sum of consecutive naturals, for example, 1474804 + ... + 1474897.

It is an arithmetic number, because the mean of its divisors is an integer number (35396424).

Almost surely, 2^138635947 is an apocalyptic number.

138635947 is a deficient number, since it is larger than the sum of its proper divisors (2949749).

138635947 is an equidigital number, since it uses as much as digits as its factorization.

138635947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2949748.

The product of its digits is 544320, while the sum is 46.

The square root of 138635947 is about 11774.3767138647. The cubic root of 138635947 is about 517.5575135811.

The spelling of 138635947 in words is "one hundred thirty-eight million, six hundred thirty-five thousand, nine hundred forty-seven".