81472705 has 8 divisors (see below), whose sum is σ = 100409832. Its totient is φ = 63416448.

The previous prime is 81472679. The next prime is 81472711. The reversal of 81472705 is 50727418.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4717584 + 76755121 = 2172^2 + 8761^2 .

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 81472705 - 2⁵ = 81472673 is a prime.

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

It is a Duffinian number.

It is an unprimeable number.

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, 220012 + ... + 220381.

It is an arithmetic number, because the mean of its divisors is an integer number (12551229).

Almost surely, 2^81472705 is an apocalyptic number.

It is an amenable number.

81472705 is a deficient number, since it is larger than the sum of its proper divisors (18937127).

81472705 is a wasteful number, since it uses less digits than its factorization.

81472705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440435.

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 81472705 is about 9026.2231858070. The cubic root of 81472705 is about 433.5149163384.

The spelling of 81472705 in words is "eighty-one million, four hundred seventy-two thousand, seven hundred five".