81810011 has 8 divisors (see below), whose sum is σ = 85681824. Its totient is φ = 77964480.

The previous prime is 81810007. The next prime is 81810013. The reversal of 81810011 is 11001818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81810011 - 2² = 81810007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81810013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50 + ... + 12791.

It is an arithmetic number, because the mean of its divisors is an integer number (10710228).

Almost surely, 2^81810011 is an apocalyptic number.

81810011 is a deficient number, since it is larger than the sum of its proper divisors (3871813).

81810011 is a wasteful number, since it uses less digits than its factorization.

81810011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13141.

The product of its (nonzero) digits is 64, while the sum is 20.

The square root of 81810011 is about 9044.8886670871. Note that the first 3 decimals coincide. The cubic root of 81810011 is about 434.1123591521.

Adding to 81810011 its reverse (11001818), we get a palindrome (92811829).

The spelling of 81810011 in words is "eighty-one million, eight hundred ten thousand, eleven".