81030705 has 64 divisors (see below), whose sum is σ = 153888768. Its totient is φ = 35642880.

The previous prime is 81030701. The next prime is 81030713. The reversal of 81030705 is 50703018.

It is not a de Polignac number, because 81030705 - 2² = 81030701 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (81030701) 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 63 ways as a sum of consecutive naturals, for example, 591397 + ... + 591533.

It is an arithmetic number, because the mean of its divisors is an integer number (2404512).

Almost surely, 2^81030705 is an apocalyptic number.

It is an amenable number.

81030705 is a deficient number, since it is larger than the sum of its proper divisors (72858063).

81030705 is a wasteful number, since it uses less digits than its factorization.

81030705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 81030705 is about 9001.7056717047. The cubic root of 81030705 is about 432.7295361275.

The spelling of 81030705 in words is "eighty-one million, thirty thousand, seven hundred five".