2021311231 has 4 divisors (see below), whose sum is σ = 2109194352. Its totient is φ = 1933428112.

The previous prime is 2021311199. The next prime is 2021311241. The reversal of 2021311231 is 1321131202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1321131202 = 2 ⋅660565601.

It is a cyclic number.

It is not a de Polignac number, because 2021311231 - 2⁵ = 2021311199 is a prime.

It is a super-2 number, since 2×2021311231² = 8171398185133470722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021311241) 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, 43941526 + ... + 43941571.

It is an arithmetic number, because the mean of its divisors is an integer number (527298588).

Almost surely, 2^2021311231 is an apocalyptic number.

2021311231 is a deficient number, since it is larger than the sum of its proper divisors (87883121).

2021311231 is an equidigital number, since it uses as much as digits as its factorization.

2021311231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87883120.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 2021311231 is about 44958.9949954400. The cubic root of 2021311231 is about 1264.3803265116.

Adding to 2021311231 its reverse (1321131202), we get a palindrome (3342442433).

The spelling of 2021311231 in words is "two billion, twenty-one million, three hundred eleven thousand, two hundred thirty-one".