81385084 has 18 divisors (see below), whose sum is σ = 156549512. Its totient is φ = 36993000.

The previous prime is 81385081. The next prime is 81385091. The reversal of 81385084 is 48058318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81385081) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 83592 + ... + 84559.

Almost surely, 2^81385084 is an apocalyptic number.

It is an amenable number.

81385084 is a deficient number, since it is larger than the sum of its proper divisors (75164428).

81385084 is a wasteful number, since it uses less digits than its factorization.

81385084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168177 (or 168164 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 37.

The square root of 81385084 is about 9021.3681889168. The cubic root of 81385084 is about 433.3594506284.

The spelling of 81385084 in words is "eighty-one million, three hundred eighty-five thousand, eighty-four".