81041216 has 14 divisors (see below), whose sum is σ = 160816290. Its totient is φ = 40520576.

The previous prime is 81041209. The next prime is 81041221. The reversal of 81041216 is 61214018.

It can be written as a sum of positive squares in only one way, i.e., 65674816 + 15366400 = 8104^2 + 3920^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81041191 and 81041200.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633071 + ... + 633198.

Almost surely, 2^81041216 is an apocalyptic number.

It is an amenable number.

81041216 is a deficient number, since it is larger than the sum of its proper divisors (79775074).

81041216 is a wasteful number, since it uses less digits than its factorization.

81041216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266281 (or 1266271 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 81041216 is about 9002.2894865695. The cubic root of 81041216 is about 432.7482460042.

The spelling of 81041216 in words is "eighty-one million, forty-one thousand, two hundred sixteen".