81939108 has 12 divisors (see below), whose sum is σ = 191191280. Its totient is φ = 27313032.

The previous prime is 81939103. The next prime is 81939131. The reversal of 81939108 is 80193918.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-3 number, since 3×81939108³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (81939103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3414118 + ... + 3414141.

Almost surely, 2^81939108 is an apocalyptic number.

It is an amenable number.

81939108 is an abundant number, since it is smaller than the sum of its proper divisors (109252172).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81939108 is a wasteful number, since it uses less digits than its factorization.

81939108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6828266 (or 6828264 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 81939108 is about 9052.0223154829. The cubic root of 81939108 is about 434.3405836680.

It can be divided in two parts, 8193910 and 8, that added together give a palindrome (8193918).

The spelling of 81939108 in words is "eighty-one million, nine hundred thirty-nine thousand, one hundred eight".