81366868 has 24 divisors (see below), whose sum is σ = 156570624. Its totient is φ = 36691200.

The previous prime is 81366839. The next prime is 81366871. The reversal of 81366868 is 86866318.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1693 + ... + 12868.

It is an arithmetic number, because the mean of its divisors is an integer number (6523776).

Almost surely, 2^81366868 is an apocalyptic number.

It is an amenable number.

81366868 is a deficient number, since it is larger than the sum of its proper divisors (75203756).

81366868 is a wasteful number, since it uses less digits than its factorization.

81366868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14703 (or 14701 counting only the distinct ones).

The product of its digits is 331776, while the sum is 46.

The square root of 81366868 is about 9020.3585294599. The cubic root of 81366868 is about 433.3271160186.

The spelling of 81366868 in words is "eighty-one million, three hundred sixty-six thousand, eight hundred sixty-eight".