81156776 has 16 divisors (see below), whose sum is σ = 161120340. Its totient is φ = 38191360.

The previous prime is 81156773. The next prime is 81156821. The reversal of 81156776 is 67765118.

It can be written as a sum of positive squares in 2 ways, for example, as 80532676 + 624100 = 8974^2 + 790^2 .

It is not an unprimeable number, because it can be changed into a prime (81156773) by changing a digit.

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, 298235 + ... + 298506.

Almost surely, 2^81156776 is an apocalyptic number.

It is an amenable number.

81156776 is a deficient number, since it is larger than the sum of its proper divisors (79963564).

81156776 is a wasteful number, since it uses less digits than its factorization.

81156776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596764 (or 596760 counting only the distinct ones).

The product of its digits is 70560, while the sum is 41.

The square root of 81156776 is about 9008.7055673942. The cubic root of 81156776 is about 432.9538394825.

The spelling of 81156776 in words is "eighty-one million, one hundred fifty-six thousand, seven hundred seventy-six".