2021121 has 6 divisors (see below), whose sum is σ = 2919410. Its totient is φ = 1347408.

The previous prime is 2021119. The next prime is 2021137. The reversal of 2021121 is 1211202.

It can be written as a sum of positive squares in only one way, i.e., 1703025 + 318096 = 1305^2 + 564^2 .

It is not a de Polignac number, because 2021121 - 2¹ = 2021119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 224569 = 2021121 / (2 + 0 + 2 + 1 + 1 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2021191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 112276 + ... + 112293.

2^2021121 is an apocalyptic number.

It is an amenable number.

2021121 is a deficient number, since it is larger than the sum of its proper divisors (898289).

2021121 is a wasteful number, since it uses less digits than its factorization.

2021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224575 (or 224572 counting only the distinct ones).

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

The square root of 2021121 is about 1421.6613520807. The cubic root of 2021121 is about 126.4340660530.

Adding to 2021121 its reverse (1211202), we get a palindrome (3232323).

The spelling of 2021121 in words is "two million, twenty-one thousand, one hundred twenty-one".