20121011 has 4 divisors (see below), whose sum is σ = 20144832. Its totient is φ = 20097192.

The previous prime is 20120999. The next prime is 20121043. The reversal of 20121011 is 11012102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11012102 = 2 ⋅5506051.

It is a cyclic number.

It is not a de Polignac number, because 20121011 - 2¹⁰ = 20119987 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20121011.

It is not an unprimeable number, because it can be changed into a prime (20121061) 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, 10595 + ... + 12348.

It is an arithmetic number, because the mean of its divisors is an integer number (5036208).

Almost surely, 2^20121011 is an apocalyptic number.

20121011 is a deficient number, since it is larger than the sum of its proper divisors (23821).

20121011 is an equidigital number, since it uses as much as digits as its factorization.

20121011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23820.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 20121011 is about 4485.6449926404. The cubic root of 20121011 is about 271.9881185338.

Adding to 20121011 its reverse (11012102), we get a palindrome (31133113).

It can be divided in two parts, 2012101 and 1, that added together give a palindrome (2012102).

The spelling of 20121011 in words is "twenty million, one hundred twenty-one thousand, eleven".