81010005 has 16 divisors (see below), whose sum is σ = 129972480. Its totient is φ = 43086528.

The previous prime is 81010003. The next prime is 81010043. The reversal of 81010005 is 50001018.

It is a happy number.

It is not a de Polignac number, because 81010005 - 2¹ = 81010003 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81010001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1645 + ... + 12834.

It is an arithmetic number, because the mean of its divisors is an integer number (8123280).

Almost surely, 2^81010005 is an apocalyptic number.

It is an amenable number.

81010005 is a deficient number, since it is larger than the sum of its proper divisors (48962475).

81010005 is a wasteful number, since it uses less digits than its factorization.

81010005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14860.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 81010005 is about 9000.5558161705. Note that the first 3 decimals coincide. The cubic root of 81010005 is about 432.6926848118.

The spelling of 81010005 in words is "eighty-one million, ten thousand, five".