81238265 has 8 divisors (see below), whose sum is σ = 97720008. Its totient is φ = 64834560.

The previous prime is 81238247. The next prime is 81238279. The reversal of 81238265 is 56283218.

It can be written as a sum of positive squares in 4 ways, for example, as 310249 + 80928016 = 557^2 + 8996^2 .

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

It is not a de Polignac number, because 81238265 - 2⁸ = 81238009 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, 17192 + ... + 21401.

It is an arithmetic number, because the mean of its divisors is an integer number (12215001).

Almost surely, 2^81238265 is an apocalyptic number.

It is an amenable number.

81238265 is a deficient number, since it is larger than the sum of its proper divisors (16481743).

81238265 is a wasteful number, since it uses less digits than its factorization.

81238265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39019.

The product of its digits is 23040, while the sum is 35.

The square root of 81238265 is about 9013.2272244740. The cubic root of 81238265 is about 433.0986997364.

The spelling of 81238265 in words is "eighty-one million, two hundred thirty-eight thousand, two hundred sixty-five".