81651116 has 12 divisors (see below), whose sum is σ = 142953888. Its totient is φ = 40807152.

The previous prime is 81651083. The next prime is 81651133. The reversal of 81651116 is 61115618.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12170 + ... + 17646.

It is an arithmetic number, because the mean of its divisors is an integer number (11912824).

Almost surely, 2^81651116 is an apocalyptic number.

It is an amenable number.

81651116 is a deficient number, since it is larger than the sum of its proper divisors (61302772).

81651116 is a wasteful number, since it uses less digits than its factorization.

81651116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9208 (or 9206 counting only the distinct ones).

The product of its digits is 1440, while the sum is 29.

The square root of 81651116 is about 9036.1007077168. The cubic root of 81651116 is about 433.8311262962.

The spelling of 81651116 in words is "eighty-one million, six hundred fifty-one thousand, one hundred sixteen".