81061066 has 16 divisors (see below), whose sum is σ = 129616200. Its totient is φ = 37888000.

The previous prime is 81061051. The next prime is 81061067. The reversal of 81061066 is 66016018.

It can be written as a sum of positive squares in 4 ways, for example, as 75325041 + 5736025 = 8679^2 + 2395^2 .

It is not an unprimeable number, because it can be changed into a prime (81061067) 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 7 ways as a sum of consecutive naturals, for example, 2935 + ... + 13066.

Almost surely, 2^81061066 is an apocalyptic number.

81061066 is a deficient number, since it is larger than the sum of its proper divisors (48555134).

81061066 is a wasteful number, since it uses less digits than its factorization.

81061066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16169.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 81061066 is about 9003.3919163835. The cubic root of 81061066 is about 432.7835751526.

The spelling of 81061066 in words is "eighty-one million, sixty-one thousand, sixty-six".