1020303521 has 4 divisors (see below), whose sum is σ = 1030822212. Its totient is φ = 1009784832.

The previous prime is 1020303517. The next prime is 1020303523. The reversal of 1020303521 is 1253030201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1253030201 = 18493 ⋅67757.

It can be written as a sum of positive squares in 2 ways, for example, as 340919296 + 679384225 = 18464^2 + 26065^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020303521 - 2² = 1020303517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1020303521.

It is not an unprimeable number, because it can be changed into a prime (1020303523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5259200 + ... + 5259393.

It is an arithmetic number, because the mean of its divisors is an integer number (257705553).

Almost surely, 2^1020303521 is an apocalyptic number.

It is an amenable number.

1020303521 is a deficient number, since it is larger than the sum of its proper divisors (10518691).

1020303521 is an equidigital number, since it uses as much as digits as its factorization.

1020303521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10518690.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 1020303521 is about 31942.1902974733. The cubic root of 1020303521 is about 1006.7225464329.

Adding to 1020303521 its reverse (1253030201), we get a palindrome (2273333722).

The spelling of 1020303521 in words is "one billion, twenty million, three hundred three thousand, five hundred twenty-one".