81563116 has 12 divisors (see below), whose sum is σ = 142813440. Its totient is φ = 40759280.

The previous prime is 81563101. The next prime is 81563117. The reversal of 81563116 is 61136518.

It is not an unprimeable number, because it can be changed into a prime (81563117) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4821 + ... + 13651.

It is an arithmetic number, because the mean of its divisors is an integer number (11901120).

Almost surely, 2^81563116 is an apocalyptic number.

It is an amenable number.

81563116 is a deficient number, since it is larger than the sum of its proper divisors (61250324).

81563116 is a wasteful number, since it uses less digits than its factorization.

81563116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11144 (or 11142 counting only the distinct ones).

The product of its digits is 4320, while the sum is 31.

The square root of 81563116 is about 9031.2300380402. The cubic root of 81563116 is about 433.6752155366.

The spelling of 81563116 in words is "eighty-one million, five hundred sixty-three thousand, one hundred sixteen".