81768416 has 12 divisors (see below), whose sum is σ = 160981632. Its totient is φ = 40884192.

The previous prime is 81768403. The next prime is 81768451. The reversal of 81768416 is 61486718.

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 as a sum of consecutive naturals, namely, 1277600 + ... + 1277663.

It is an arithmetic number, because the mean of its divisors is an integer number (13415136).

Almost surely, 2^81768416 is an apocalyptic number.

It is an amenable number.

81768416 is a deficient number, since it is larger than the sum of its proper divisors (79213216).

81768416 is a wasteful number, since it uses less digits than its factorization.

81768416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2555273 (or 2555265 counting only the distinct ones).

The product of its digits is 64512, while the sum is 41.

The square root of 81768416 is about 9042.5890097914. The cubic root of 81768416 is about 434.0387741696.

The spelling of 81768416 in words is "eighty-one million, seven hundred sixty-eight thousand, four hundred sixteen".