81023105 has 16 divisors (see below), whose sum is σ = 103375440. Its totient is φ = 60751872.

The previous prime is 81023083. The next prime is 81023113. The reversal of 81023105 is 50132018.

It can be written as a sum of positive squares in 8 ways, for example, as 6390784 + 74632321 = 2528^2 + 8639^2 .

It is a cyclic number.

It is not a de Polignac number, because 81023105 - 2¹⁴ = 81006721 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19991 + ... + 23699.

It is an arithmetic number, because the mean of its divisors is an integer number (6460965).

Almost surely, 2^81023105 is an apocalyptic number.

81023105 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81023105 is a deficient number, since it is larger than the sum of its proper divisors (22352335).

81023105 is a wasteful number, since it uses less digits than its factorization.

81023105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3988.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 81023105 is about 9001.2835195876. The cubic root of 81023105 is about 432.7160069050.

The spelling of 81023105 in words is "eighty-one million, twenty-three thousand, one hundred five".