81210485 has 4 divisors (see below), whose sum is σ = 97452588. Its totient is φ = 64968384.

The previous prime is 81210473. The next prime is 81210487. The reversal of 81210485 is 58401218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58401218 = 2 ⋅29200609.

It can be written as a sum of positive squares in 2 ways, for example, as 25170289 + 56040196 = 5017^2 + 7486^2 .

It is a cyclic number.

It is not a de Polignac number, because 81210485 - 2⁸ = 81210229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81210487) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8121044 + ... + 8121053.

It is an arithmetic number, because the mean of its divisors is an integer number (24363147).

Almost surely, 2^81210485 is an apocalyptic number.

It is an amenable number.

81210485 is a deficient number, since it is larger than the sum of its proper divisors (16242103).

81210485 is a wasteful number, since it uses less digits than its factorization.

81210485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16242102.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 81210485 is about 9011.6860242687. The cubic root of 81210485 is about 433.0493270524.

The spelling of 81210485 in words is "eighty-one million, two hundred ten thousand, four hundred eighty-five".