81939255 has 8 divisors (see below), whose sum is σ = 131102832. Its totient is φ = 43700928.

The previous prime is 81939241. The next prime is 81939301. The reversal of 81939255 is 55293918.

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

It is not a de Polignac number, because 81939255 - 2¹⁰ = 81938231 is a prime.

It is a congruent 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, 2731294 + ... + 2731323.

It is an arithmetic number, because the mean of its divisors is an integer number (16387854).

Almost surely, 2^81939255 is an apocalyptic number.

81939255 is a deficient number, since it is larger than the sum of its proper divisors (49163577).

81939255 is a wasteful number, since it uses less digits than its factorization.

81939255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5462625.

The product of its digits is 97200, while the sum is 42.

The square root of 81939255 is about 9052.0304352118. The cubic root of 81939255 is about 434.3408434057.

The spelling of 81939255 in words is "eighty-one million, nine hundred thirty-nine thousand, two hundred fifty-five".