138477831 has 4 divisors (see below), whose sum is σ = 184637112. Its totient is φ = 92318552.

The previous prime is 138477827. The next prime is 138477881. The reversal of 138477831 is 138774831.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 138477831 - 2² = 138477827 is a prime.

It is a super-2 number, since 2×138477831² = 38352219356929122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138477821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23079636 + ... + 23079641.

It is an arithmetic number, because the mean of its divisors is an integer number (46159278).

Almost surely, 2^138477831 is an apocalyptic number.

138477831 is a deficient number, since it is larger than the sum of its proper divisors (46159281).

138477831 is an equidigital number, since it uses as much as digits as its factorization.

138477831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46159280.

The product of its digits is 112896, while the sum is 42.

The square root of 138477831 is about 11767.6603876896. The cubic root of 138477831 is about 517.3606784979.

The spelling of 138477831 in words is "one hundred thirty-eight million, four hundred seventy-seven thousand, eight hundred thirty-one".