81770216 has 16 divisors (see below), whose sum is σ = 167257440. Its totient is φ = 37168240.

The previous prime is 81770201. The next prime is 81770233. The reversal of 81770216 is 61207718.

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 in 3 ways as a sum of consecutive naturals, for example, 464516 + ... + 464691.

It is an arithmetic number, because the mean of its divisors is an integer number (10453590).

Almost surely, 2^81770216 is an apocalyptic number.

It is an amenable number.

81770216 is an abundant number, since it is smaller than the sum of its proper divisors (85487224).

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

81770216 is a wasteful number, since it uses less digits than its factorization.

81770216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 929224 (or 929220 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 81770216 is about 9042.6885382612. The cubic root of 81770216 is about 434.0419590344.

It can be divided in two parts, 817702 and 16, that added together give a palindrome (817718).

The spelling of 81770216 in words is "eighty-one million, seven hundred seventy thousand, two hundred sixteen".