81144011 has 4 divisors (see below), whose sum is σ = 87385872. Its totient is φ = 74902152.

The previous prime is 81143999. The next prime is 81144013. The reversal of 81144011 is 11044118.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81144011 - 2⁶ = 81143947 is a prime.

It is a super-3 number, since 3×81144011³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81144013) 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 3 ways as a sum of consecutive naturals, for example, 3120911 + ... + 3120936.

It is an arithmetic number, because the mean of its divisors is an integer number (21846468).

Almost surely, 2^81144011 is an apocalyptic number.

81144011 is a deficient number, since it is larger than the sum of its proper divisors (6241861).

81144011 is a wasteful number, since it uses less digits than its factorization.

81144011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6241860.

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 81144011 is about 9007.9970581700. The cubic root of 81144011 is about 432.9311387880.

Adding to 81144011 its reverse (11044118), we get a palindrome (92188129).

The spelling of 81144011 in words is "eighty-one million, one hundred forty-four thousand, eleven".