81786480 has 40 divisors (see below), whose sum is σ = 253538832. Its totient is φ = 21809664.

The previous prime is 81786451. The next prime is 81786553. The reversal of 81786480 is 8468718.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170149 + ... + 170628.

Almost surely, 2^81786480 is an apocalyptic number.

81786480 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81786480 is an abundant number, since it is smaller than the sum of its proper divisors (171752352).

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

81786480 is a wasteful number, since it uses less digits than its factorization.

81786480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340793 (or 340787 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 42.

The square root of 81786480 is about 9043.5877836177. The cubic root of 81786480 is about 434.0707339389.

The spelling of 81786480 in words is "eighty-one million, seven hundred eighty-six thousand, four hundred eighty".