81012011 has 4 divisors (see below), whose sum is σ = 81048024. Its totient is φ = 80976000.

The previous prime is 81011989. The next prime is 81012013. The reversal of 81012011 is 11021018.

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

It is a cyclic number.

It is not a de Polignac number, because 81012011 - 2¹⁰ = 81010987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81012013) 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, 14390 + ... + 19211.

It is an arithmetic number, because the mean of its divisors is an integer number (20262006).

Almost surely, 2^81012011 is an apocalyptic number.

81012011 is a deficient number, since it is larger than the sum of its proper divisors (36013).

81012011 is a wasteful number, since it uses less digits than its factorization.

81012011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36012.

The product of its (nonzero) digits is 16, while the sum is 14.

The square root of 81012011 is about 9000.6672530430. The cubic root of 81012011 is about 432.6962562816.

Adding to 81012011 its reverse (11021018), we get a palindrome (92033029).

It can be divided in two parts, 810 and 12011, that added together give a palindrome (12821).

The spelling of 81012011 in words is "eighty-one million, twelve thousand, eleven".