81273105 has 32 divisors (see below), whose sum is σ = 147571200. Its totient is φ = 42420096.

The previous prime is 81273097. The next prime is 81273113. The reversal of 81273105 is 50137218.

It is an interprime number because it is at equal distance from previous prime (81273097) and next prime (81273113).

It is not a de Polignac number, because 81273105 - 2³ = 81273097 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 60 + ... + 12749.

It is an arithmetic number, because the mean of its divisors is an integer number (4611600).

Almost surely, 2^81273105 is an apocalyptic number.

It is an amenable number.

81273105 is a deficient number, since it is larger than the sum of its proper divisors (66298095).

81273105 is a wasteful number, since it uses less digits than its factorization.

81273105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12870 (or 12864 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 81273105 is about 9015.1597323619. The cubic root of 81273105 is about 433.1606040708.

The spelling of 81273105 in words is "eighty-one million, two hundred seventy-three thousand, one hundred five".