81541138 has 16 divisors (see below), whose sum is σ = 141171264. Its totient is φ = 34599600.

The previous prime is 81541133. The next prime is 81541151. The reversal of 81541138 is 83114518.

It is not an unprimeable number, because it can be changed into a prime (81541133) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 27420 + ... + 30247.

It is an arithmetic number, because the mean of its divisors is an integer number (8823204).

Almost surely, 2^81541138 is an apocalyptic number.

81541138 is a deficient number, since it is larger than the sum of its proper divisors (59630126).

81541138 is a wasteful number, since it uses less digits than its factorization.

81541138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57777.

The product of its digits is 3840, while the sum is 31.

The square root of 81541138 is about 9030.0131782850. The cubic root of 81541138 is about 433.6362593246.

The spelling of 81541138 in words is "eighty-one million, five hundred forty-one thousand, one hundred thirty-eight".