81400768 has 28 divisors (see below), whose sum is σ = 162445192. Its totient is φ = 40469760.

The previous prime is 81400729. The next prime is 81400799. The reversal of 81400768 is 86700418.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8071 + ... + 15097.

It is an arithmetic number, because the mean of its divisors is an integer number (5801614).

Almost surely, 2^81400768 is an apocalyptic number.

It is an amenable number.

81400768 is a deficient number, since it is larger than the sum of its proper divisors (81044424).

81400768 is a wasteful number, since it uses less digits than its factorization.

81400768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7220 (or 7210 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 81400768 is about 9022.2374165170. The cubic root of 81400768 is about 433.3872869047.

The spelling of 81400768 in words is "eighty-one million, four hundred thousand, seven hundred sixty-eight".