81849216 has 32 divisors (see below), whose sum is σ = 217413000. Its totient is φ = 27282944.

The previous prime is 81849211. The next prime is 81849227. The reversal of 81849216 is 61294818.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81849211) by changing a digit.

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, 106191 + ... + 106958.

Almost surely, 2^81849216 is an apocalyptic number.

It is an amenable number.

81849216 is an abundant number, since it is smaller than the sum of its proper divisors (135563784).

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

81849216 is a wasteful number, since it uses less digits than its factorization.

81849216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213166 (or 213154 counting only the distinct ones).

The product of its digits is 27648, while the sum is 39.

The square root of 81849216 is about 9047.0556536367. The cubic root of 81849216 is about 434.1816931977.

The spelling of 81849216 in words is "eighty-one million, eight hundred forty-nine thousand, two hundred sixteen".