81205485 has 8 divisors (see below), whose sum is σ = 129928800. Its totient is φ = 43309584.

The previous prime is 81205429. The next prime is 81205489. The reversal of 81205485 is 58450218.

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

It is a de Polignac number, because none of the positive numbers 2^k-81205485 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81205489) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2706835 + ... + 2706864.

It is an arithmetic number, because the mean of its divisors is an integer number (16241100).

Almost surely, 2^81205485 is an apocalyptic number.

It is an amenable number.

81205485 is a deficient number, since it is larger than the sum of its proper divisors (48723315).

81205485 is a wasteful number, since it uses less digits than its factorization.

81205485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5413707.

The product of its (nonzero) digits is 12800, while the sum is 33.

The square root of 81205485 is about 9011.4086024328. The cubic root of 81205485 is about 433.0404394846.

The spelling of 81205485 in words is "eighty-one million, two hundred five thousand, four hundred eighty-five".