20303431021 has 4 divisors (see below), whose sum is σ = 20303791200. Its totient is φ = 20303070844.

The previous prime is 20303431009. The next prime is 20303431051. The reversal of 20303431021 is 12013430302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20303431021 is a prime.

It is a super-2 number, since 2×20303431021² (a number of 21 digits) contains 22 as substring.

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 20303431021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20303431051) 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 3 ways as a sum of consecutive naturals, for example, 75151 + ... + 215068.

It is an arithmetic number, because the mean of its divisors is an integer number (5075947800).

Almost surely, 2^20303431021 is an apocalyptic number.

It is an amenable number.

20303431021 is a deficient number, since it is larger than the sum of its proper divisors (360179).

20303431021 is an equidigital number, since it uses as much as digits as its factorization.

20303431021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360178.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 20303431021 its reverse (12013430302), we get a palindrome (32316861323).

The spelling of 20303431021 in words is "twenty billion, three hundred three million, four hundred thirty-one thousand, twenty-one".