20010121 has 4 divisors (see below), whose sum is σ = 20137732. Its totient is φ = 19882512.

The previous prime is 20010079. The next prime is 20010127. The reversal of 20010121 is 12101002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12101002 = 2 ⋅6050501.

It can be written as a sum of positive squares in 2 ways, for example, as 15327225 + 4682896 = 3915^2 + 2164^2 .

It is a cyclic number.

It is not a de Polignac number, because 20010121 - 2¹¹ = 20008073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20010127) 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, 63570 + ... + 63883.

It is an arithmetic number, because the mean of its divisors is an integer number (5034433).

Almost surely, 2^20010121 is an apocalyptic number.

It is an amenable number.

20010121 is a deficient number, since it is larger than the sum of its proper divisors (127611).

20010121 is a wasteful number, since it uses less digits than its factorization.

20010121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127610.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 20010121 is about 4473.2673740790. The cubic root of 20010121 is about 271.4875416392.

Adding to 20010121 its reverse (12101002), we get a palindrome (32111123).

The spelling of 20010121 in words is "twenty million, ten thousand, one hundred twenty-one".