81005310 has 48 divisors (see below), whose sum is σ = 219776544. Its totient is φ = 20661696.

The previous prime is 81005279. The next prime is 81005311. The reversal of 81005310 is 1350018.

It is a happy number.

It is a super-2 number, since 2×81005310² = 13123720496392200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81005311) 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, 17497 + ... + 21636.

It is an arithmetic number, because the mean of its divisors is an integer number (4578678).

Almost surely, 2^81005310 is an apocalyptic number.

81005310 is an abundant number, since it is smaller than the sum of its proper divisors (138771234).

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

81005310 is a wasteful number, since it uses less digits than its factorization.

81005310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39169 (or 39166 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 81005310 is about 9000.2949951654. The cubic root of 81005310 is about 432.6843256328.

Adding to 81005310 its reverse (1350018), we get a palindrome (82355328).

The spelling of 81005310 in words is "eighty-one million, five thousand, three hundred ten".