81275966 has 4 divisors (see below), whose sum is σ = 121913952. Its totient is φ = 40637982.

The previous prime is 81275933. The next prime is 81275983. The reversal of 81275966 is 66957218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66957218 = 2 ⋅33478609.

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 as a sum of consecutive naturals, namely, 20318990 + ... + 20318993.

It is an arithmetic number, because the mean of its divisors is an integer number (30478488).

Almost surely, 2^81275966 is an apocalyptic number.

81275966 is a deficient number, since it is larger than the sum of its proper divisors (40637986).

81275966 is a wasteful number, since it uses less digits than its factorization.

81275966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40637985.

The product of its digits is 181440, while the sum is 44.

The square root of 81275966 is about 9015.3184081318. The cubic root of 81275966 is about 433.1656867606.

The spelling of 81275966 in words is "eighty-one million, two hundred seventy-five thousand, nine hundred sixty-six".