81274205 has 4 divisors (see below), whose sum is σ = 97529052. Its totient is φ = 65019360.

The previous prime is 81274183. The next prime is 81274213. The reversal of 81274205 is 50247218.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8922169 + 72352036 = 2987^2 + 8506^2 .

It is not a de Polignac number, because 81274205 - 2⁸ = 81273949 is a prime.

It is a Duffinian number.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 8127416 + ... + 8127425.

It is an arithmetic number, because the mean of its divisors is an integer number (24382263).

Almost surely, 2^81274205 is an apocalyptic number.

It is an amenable number.

81274205 is a deficient number, since it is larger than the sum of its proper divisors (16254847).

81274205 is a wasteful number, since it uses less digits than its factorization.

81274205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16254846.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 81274205 is about 9015.2207405033. The cubic root of 81274205 is about 433.1625582823.

The spelling of 81274205 in words is "eighty-one million, two hundred seventy-four thousand, two hundred five".