81856776 has 16 divisors (see below), whose sum is σ = 204642000. Its totient is φ = 27285584.

The previous prime is 81856759. The next prime is 81856811. The reversal of 81856776 is 67765818.

It is a super-2 number, since 2×81856776² = 13401063554228352, which contains 22 as substring.

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, 1705326 + ... + 1705373.

It is an arithmetic number, because the mean of its divisors is an integer number (12790125).

Almost surely, 2^81856776 is an apocalyptic number.

It is an amenable number.

81856776 is an abundant number, since it is smaller than the sum of its proper divisors (122785224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81856776 is a wasteful number, since it uses less digits than its factorization.

81856776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3410708 (or 3410704 counting only the distinct ones).

The product of its digits is 564480, while the sum is 48.

The square root of 81856776 is about 9047.4734594803. The cubic root of 81856776 is about 434.1950605118.

The spelling of 81856776 in words is "eighty-one million, eight hundred fifty-six thousand, seven hundred seventy-six".