81682868 has 12 divisors (see below), whose sum is σ = 143463012. Its totient is φ = 40693440.

The previous prime is 81682831. The next prime is 81682871. The reversal of 81682868 is 86828618.

It can be written as a sum of positive squares in 2 ways, for example, as 17073424 + 64609444 = 4132^2 + 8038^2 .

It is a congruent number.

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, 35753 + ... + 37968.

It is an arithmetic number, because the mean of its divisors is an integer number (11955251).

Almost surely, 2^81682868 is an apocalyptic number.

It is an amenable number.

81682868 is a deficient number, since it is larger than the sum of its proper divisors (61780144).

81682868 is a wasteful number, since it uses less digits than its factorization.

81682868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74002 (or 74000 counting only the distinct ones).

The product of its digits is 294912, while the sum is 47.

The square root of 81682868 is about 9037.8574894717. The cubic root of 81682868 is about 433.8873542304.

The spelling of 81682868 in words is "eighty-one million, six hundred eighty-two thousand, eight hundred sixty-eight".