2021013121 has 4 divisors (see below), whose sum is σ = 2022377392. Its totient is φ = 2019648852.

The previous prime is 2021013107. The next prime is 2021013179. The reversal of 2021013121 is 1213101202.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1213101202 = 2 ⋅606550601.

It is a cyclic number.

It is not a de Polignac number, because 2021013121 - 2¹³ = 2021004929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2021013221) 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, 679911 + ... + 682876.

It is an arithmetic number, because the mean of its divisors is an integer number (505594348).

Almost surely, 2^2021013121 is an apocalyptic number.

It is an amenable number.

2021013121 is a deficient number, since it is larger than the sum of its proper divisors (1364271).

2021013121 is a wasteful number, since it uses less digits than its factorization.

2021013121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1364270.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 2021013121 is about 44955.6795188328. The cubic root of 2021013121 is about 1264.3181650551.

Adding to 2021013121 its reverse (1213101202), we get a palindrome (3234114323).

The spelling of 2021013121 in words is "two billion, twenty-one million, thirteen thousand, one hundred twenty-one".