4020303521 has 4 divisors (see below), whose sum is σ = 4329557652. Its totient is φ = 3711049392.

The previous prime is 4020303509. The next prime is 4020303527. The reversal of 4020303521 is 1253030204.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1053976225 + 2966327296 = 32465^2 + 54464^2 .

It is a cyclic number.

It is not a de Polignac number, because 4020303521 - 2¹⁴ = 4020287137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4020303493 and 4020303502.

It is not an unprimeable number, because it can be changed into a prime (4020303527) 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, 154627046 + ... + 154627071.

It is an arithmetic number, because the mean of its divisors is an integer number (1082389413).

Almost surely, 2^4020303521 is an apocalyptic number.

It is an amenable number.

4020303521 is a deficient number, since it is larger than the sum of its proper divisors (309254131).

4020303521 is a wasteful number, since it uses less digits than its factorization.

4020303521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309254130.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 4020303521 is about 63405.8634591471. The cubic root of 4020303521 is about 1590.0823396569.

Adding to 4020303521 its reverse (1253030204), we get a palindrome (5273333725).

The spelling of 4020303521 in words is "four billion, twenty million, three hundred three thousand, five hundred twenty-one".