20012121 has 12 divisors (see below), whose sum is σ = 29075748. Its totient is φ = 13263264.

The previous prime is 20012119. The next prime is 20012171. The reversal of 20012121 is 12121002.

It can be written as a sum of positive squares in 2 ways, for example, as 12110400 + 7901721 = 3480^2 + 2811^2 .

It is not a de Polignac number, because 20012121 - 2¹ = 20012119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (20012101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4870 + ... + 7983.

It is an arithmetic number, because the mean of its divisors is an integer number (2422979).

Almost surely, 2^20012121 is an apocalyptic number.

It is an amenable number.

20012121 is a deficient number, since it is larger than the sum of its proper divisors (9063627).

20012121 is a wasteful number, since it uses less digits than its factorization.

20012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13032 (or 13029 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 20012121 is about 4473.4909187345. The cubic root of 20012121 is about 271.4965863454.

Adding to 20012121 its reverse (12121002), we get a palindrome (32133123).

It can be divided in two parts, 200 and 12121, that added together give a palindrome (12321).

The spelling of 20012121 in words is "twenty million, twelve thousand, one hundred twenty-one".