20090121 has 4 divisors (see below), whose sum is σ = 26786832. Its totient is φ = 13393412.

The previous prime is 20090099. The next prime is 20090129. The reversal of 20090121 is 12109002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20090121 - 2⁹ = 20089609 is a prime.

It is a super-2 number, since 2×20090121² = 807225923589282, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20090121.

It is not an unprimeable number, because it can be changed into a prime (20090129) 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, 3348351 + ... + 3348356.

It is an arithmetic number, because the mean of its divisors is an integer number (6696708).

Almost surely, 2^20090121 is an apocalyptic number.

It is an amenable number.

20090121 is a deficient number, since it is larger than the sum of its proper divisors (6696711).

20090121 is an equidigital number, since it uses as much as digits as its factorization.

20090121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6696710.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 20090121 is about 4482.2004640578. The cubic root of 20090121 is about 271.8488608507.

Adding to 20090121 its reverse (12109002), we get a palindrome (32199123).

The spelling of 20090121 in words is "twenty million, ninety thousand, one hundred twenty-one".