81041816 has 16 divisors (see below), whose sum is σ = 152139840. Its totient is φ = 40471200.

The previous prime is 81041813. The next prime is 81041819. The reversal of 81041816 is 61814018.

It is an interprime number because it is at equal distance from previous prime (81041813) and next prime (81041819).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81041813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1241 + ... + 12791.

It is an arithmetic number, because the mean of its divisors is an integer number (9508740).

Almost surely, 2^81041816 is an apocalyptic number.

It is an amenable number.

81041816 is a deficient number, since it is larger than the sum of its proper divisors (71098024).

81041816 is a wasteful number, since it uses less digits than its factorization.

81041816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12434 (or 12430 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 29.

The square root of 81041816 is about 9002.3228113637. The cubic root of 81041816 is about 432.7493139723.

The spelling of 81041816 in words is "eighty-one million, forty-one thousand, eight hundred sixteen".