81185763 has 16 divisors (see below), whose sum is σ = 111044736. Its totient is φ = 52731840.

The previous prime is 81185747. The next prime is 81185773. The reversal of 81185763 is 36758118.

It is not a de Polignac number, because 81185763 - 2⁴ = 81185747 is a prime.

It is a super-2 number, since 2×81185763² = 13182256227784338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81185743) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97756 + ... + 98582.

It is an arithmetic number, because the mean of its divisors is an integer number (6940296).

Almost surely, 2^81185763 is an apocalyptic number.

81185763 is a deficient number, since it is larger than the sum of its proper divisors (29858973).

81185763 is a wasteful number, since it uses less digits than its factorization.

81185763 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1634.

The product of its digits is 40320, while the sum is 39.

The square root of 81185763 is about 9010.3142564508. The cubic root of 81185763 is about 433.0053798043.

The spelling of 81185763 in words is "eighty-one million, one hundred eighty-five thousand, seven hundred sixty-three".