81939835 has 8 divisors (see below), whose sum is σ = 98649936. Its totient is φ = 65337120.

The previous prime is 81939829. The next prime is 81939857. The reversal of 81939835 is 53893918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81939835 - 2⁷ = 81939707 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25156 + ... + 28225.

It is an arithmetic number, because the mean of its divisors is an integer number (12331242).

Almost surely, 2^81939835 is an apocalyptic number.

81939835 is a deficient number, since it is larger than the sum of its proper divisors (16710101).

81939835 is a wasteful number, since it uses less digits than its factorization.

81939835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53693.

The product of its digits is 233280, while the sum is 46.

The square root of 81939835 is about 9052.0624721662. The cubic root of 81939835 is about 434.3418682181.

The spelling of 81939835 in words is "eighty-one million, nine hundred thirty-nine thousand, eight hundred thirty-five".