81782886 has 32 divisors (see below), whose sum is σ = 173592288. Its totient is φ = 25597440.

The previous prime is 81782873. The next prime is 81782887. The reversal of 81782886 is 68828718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81782887) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66816 + ... + 68028.

It is an arithmetic number, because the mean of its divisors is an integer number (5424759).

Almost surely, 2^81782886 is an apocalyptic number.

81782886 is an abundant number, since it is smaller than the sum of its proper divisors (91809402).

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

81782886 is a wasteful number, since it uses less digits than its factorization.

81782886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1896.

The product of its digits is 344064, while the sum is 48.

The square root of 81782886 is about 9043.3890771104. The cubic root of 81782886 is about 434.0643756220.

The spelling of 81782886 in words is "eighty-one million, seven hundred eighty-two thousand, eight hundred eighty-six".