81270705 has 8 divisors (see below), whose sum is σ = 130033152. Its totient is φ = 43344368.

The previous prime is 81270703. The next prime is 81270719. The reversal of 81270705 is 50707218.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81270705 - 2¹ = 81270703 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81270703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2709009 + ... + 2709038.

It is an arithmetic number, because the mean of its divisors is an integer number (16254144).

Almost surely, 2^81270705 is an apocalyptic number.

It is an amenable number.

81270705 is a deficient number, since it is larger than the sum of its proper divisors (48762447).

81270705 is a wasteful number, since it uses less digits than its factorization.

81270705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5418055.

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 81270705 is about 9015.0266222569. The cubic root of 81270705 is about 433.1563402753.

It can be divided in two parts, 812 and 70705, that added together give a palindrome (71517).

The spelling of 81270705 in words is "eighty-one million, two hundred seventy thousand, seven hundred five".