20080121 has 4 divisors (see below), whose sum is σ = 20090532. Its totient is φ = 20069712.

The previous prime is 20080117. The next prime is 20080129. The reversal of 20080121 is 12108002.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12108002 = 2 ⋅6054001.

It can be written as a sum of positive squares in 2 ways, for example, as 3474496 + 16605625 = 1864^2 + 4075^2 .

It is a cyclic number.

It is not a de Polignac number, because 20080121 - 2² = 20080117 is a prime.

It is a super-2 number, since 2×20080121² = 806422518749282, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20080096 and 20080105.

It is not an unprimeable number, because it can be changed into a prime (20080129) 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, 1370 + ... + 6483.

It is an arithmetic number, because the mean of its divisors is an integer number (5022633).

Almost surely, 2^20080121 is an apocalyptic number.

It is an amenable number.

20080121 is a deficient number, since it is larger than the sum of its proper divisors (10411).

20080121 is an equidigital number, since it uses as much as digits as its factorization.

20080121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10410.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 20080121 is about 4481.0848016970. The cubic root of 20080121 is about 271.8037484663.

Adding to 20080121 its reverse (12108002), we get a palindrome (32188123).

The spelling of 20080121 in words is "twenty million, eighty thousand, one hundred twenty-one".