2021123101 has 4 divisors (see below), whose sum is σ = 2024626492. Its totient is φ = 2017619712.

The previous prime is 2021123099. The next prime is 2021123131. The reversal of 2021123101 is 1013211202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1013211202 = 2 ⋅506605601.

It can be written as a sum of positive squares in 2 ways, for example, as 1829272900 + 191850201 = 42770^2 + 13851^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021123101 - 2¹ = 2021123099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021123131) 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, 1750830 + ... + 1751983.

It is an arithmetic number, because the mean of its divisors is an integer number (506156623).

Almost surely, 2^2021123101 is an apocalyptic number.

It is an amenable number.

2021123101 is a deficient number, since it is larger than the sum of its proper divisors (3503391).

2021123101 is an equidigital number, since it uses as much as digits as its factorization.

2021123101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3503390.

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

The square root of 2021123101 is about 44956.9027069259. The cubic root of 2021123101 is about 1264.3410986336.

Adding to 2021123101 its reverse (1013211202), we get a palindrome (3034334303).

The spelling of 2021123101 in words is "two billion, twenty-one million, one hundred twenty-three thousand, one hundred one".