81784056 has 32 divisors (see below), whose sum is σ = 215222400. Its totient is φ = 25826400.

The previous prime is 81784033. The next prime is 81784057. The reversal of 81784056 is 65048718.

It is a super-2 number, since 2×81784056² = 13377263631622272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81784057) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89220 + ... + 90131.

It is an arithmetic number, because the mean of its divisors is an integer number (6725700).

Almost surely, 2^81784056 is an apocalyptic number.

It is an amenable number.

81784056 is an abundant number, since it is smaller than the sum of its proper divisors (133438344).

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

81784056 is a wasteful number, since it uses less digits than its factorization.

81784056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179379 (or 179375 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 81784056 is about 9043.4537650170. The cubic root of 81784056 is about 434.0664455452.

The spelling of 81784056 in words is "eighty-one million, seven hundred eighty-four thousand, fifty-six".