81339838 has 24 divisors (see below), whose sum is σ = 129876552. Its totient is φ = 38176992.

The previous prime is 81339829. The next prime is 81339847. The reversal of 81339838 is 83893318.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81339829) and next prime (81339847).

It is a junction number, because it is equal to n+sod(n) for n = 81339794 and 81339803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61581 + ... + 62887.

It is an arithmetic number, because the mean of its divisors is an integer number (5411523).

Almost surely, 2^81339838 is an apocalyptic number.

81339838 is a deficient number, since it is larger than the sum of its proper divisors (48536714).

81339838 is a wasteful number, since it uses less digits than its factorization.

81339838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404 (or 1375 counting only the distinct ones).

The product of its digits is 124416, while the sum is 43.

The square root of 81339838 is about 9018.8601275327. The cubic root of 81339838 is about 433.2791270789.

It can be divided in two parts, 8133 and 9838, that added together give a palindrome (17971).

The spelling of 81339838 in words is "eighty-one million, three hundred thirty-nine thousand, eight hundred thirty-eight".