81281608 has 16 divisors (see below), whose sum is σ = 152512380. Its totient is φ = 40611648.

The previous prime is 81281593. The next prime is 81281623. The reversal of 81281608 is 80618218.

It is an interprime number because it is at equal distance from previous prime (81281593) and next prime (81281623).

It can be written as a sum of positive squares in 2 ways, for example, as 80676324 + 605284 = 8982^2 + 778^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12310 + ... + 17722.

Almost surely, 2^81281608 is an apocalyptic number.

It is an amenable number.

81281608 is a deficient number, since it is larger than the sum of its proper divisors (71230772).

81281608 is a wasteful number, since it uses less digits than its factorization.

81281608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7296 (or 7292 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 34.

The square root of 81281608 is about 9015.6313145558. The cubic root of 81281608 is about 433.1757096672.

The spelling of 81281608 in words is "eighty-one million, two hundred eighty-one thousand, six hundred eight".