20121812 has 12 divisors (see below), whose sum is σ = 37284660. Its totient is φ = 9469056.

The previous prime is 20121811. The next prime is 20121823. The reversal of 20121812 is 21812102.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 8737936 + 11383876 = 2956^2 + 3374^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121811) 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, 147887 + ... + 148022.

It is an arithmetic number, because the mean of its divisors is an integer number (3107055).

Almost surely, 2^20121812 is an apocalyptic number.

It is an amenable number.

20121812 is a deficient number, since it is larger than the sum of its proper divisors (17162848).

20121812 is a wasteful number, since it uses less digits than its factorization.

20121812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295930 (or 295928 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 20121812 is about 4485.7342765706. The cubic root of 20121812 is about 271.9917276896.

Adding to 20121812 its reverse (21812102), we get a palindrome (41933914).

The spelling of 20121812 in words is "twenty million, one hundred twenty-one thousand, eight hundred twelve".