2021521431 has 8 divisors (see below), whose sum is σ = 2701185280. Its totient is φ = 1344769272.

The previous prime is 2021521429. The next prime is 2021521483. The reversal of 2021521431 is 1341251202.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2021521431 - 2¹ = 2021521429 is a prime.

It is a super-3 number, since 3×2021521431³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021521398 and 2021521407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021521421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 726301 + ... + 729078.

It is an arithmetic number, because the mean of its divisors is an integer number (337648160).

Almost surely, 2^2021521431 is an apocalyptic number.

2021521431 is a deficient number, since it is larger than the sum of its proper divisors (679663849).

2021521431 is a wasteful number, since it uses less digits than its factorization.

2021521431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1455845.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 2021521431 is about 44961.3326203750. The cubic root of 2021521431 is about 1264.4241534309.

Adding to 2021521431 its reverse (1341251202), we get a palindrome (3362772633).

The spelling of 2021521431 in words is "two billion, twenty-one million, five hundred twenty-one thousand, four hundred thirty-one".