81116784 has 60 divisors (see below), whose sum is σ = 259448176. Its totient is φ = 23175936.

The previous prime is 81116773. The next prime is 81116803. The reversal of 81116784 is 48761118.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39229 + ... + 41244.

Almost surely, 2^81116784 is an apocalyptic number.

81116784 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

81116784 is an abundant number, since it is smaller than the sum of its proper divisors (178331392).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81116784 is a wasteful number, since it uses less digits than its factorization.

81116784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80494 (or 80485 counting only the distinct ones).

The product of its digits is 10752, while the sum is 36.

The square root of 81116784 is about 9006.4856631208. The cubic root of 81116784 is about 432.8827115757.

The spelling of 81116784 in words is "eighty-one million, one hundred sixteen thousand, seven hundred eighty-four".