81766808 has 16 divisors (see below), whose sum is σ = 153550680. Its totient is φ = 40819968.

The previous prime is 81766807. The next prime is 81766847. The reversal of 81766808 is 80866718.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81766801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2210 + ... + 12977.

Almost surely, 2^81766808 is an apocalyptic number.

It is an amenable number.

81766808 is a deficient number, since it is larger than the sum of its proper divisors (71783872).

81766808 is a wasteful number, since it uses less digits than its factorization.

81766808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15866 (or 15862 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 44.

The square root of 81766808 is about 9042.5000967653. The cubic root of 81766808 is about 434.0359289841.

The spelling of 81766808 in words is "eighty-one million, seven hundred sixty-six thousand, eight hundred eight".