81385080 has 96 divisors (see below), whose sum is σ = 284037840. Its totient is φ = 18600960.

The previous prime is 81385079. The next prime is 81385081. The reversal of 81385080 is 8058318.

It is an interprime number because it is at equal distance from previous prime (81385079) and next prime (81385081).

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 23 ways as a sum of consecutive naturals, for example, 1041 + ... + 12800.

Almost surely, 2^81385080 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81385080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142018920).

81385080 is an abundant number, since it is smaller than the sum of its proper divisors (202652760).

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

81385080 is a wasteful number, since it uses less digits than its factorization.

81385080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13869 (or 13858 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 81385080 is about 9021.3679672209. The cubic root of 81385080 is about 433.3594435286.

The spelling of 81385080 in words is "eighty-one million, three hundred eighty-five thousand, eighty".