81475766 has 16 divisors (see below), whose sum is σ = 124312320. Its totient is φ = 40041960.

The previous prime is 81475763. The next prime is 81475777. The reversal of 81475766 is 66757418.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81475763) 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, 61685 + ... + 62991.

It is an arithmetic number, because the mean of its divisors is an integer number (7769520).

Almost surely, 2^81475766 is an apocalyptic number.

81475766 is a deficient number, since it is larger than the sum of its proper divisors (42836554).

81475766 is a wasteful number, since it uses less digits than its factorization.

81475766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1819.

The product of its digits is 282240, while the sum is 44.

The square root of 81475766 is about 9026.3927457207. The cubic root of 81475766 is about 433.5203454472.

The spelling of 81475766 in words is "eighty-one million, four hundred seventy-five thousand, seven hundred sixty-six".