20431431021 has 16 divisors (see below), whose sum is σ = 27448544448. Its totient is φ = 13517692800.

The previous prime is 20431430993. The next prime is 20431431029. The reversal of 20431431021 is 12013413402.

It is not a de Polignac number, because 20431431021 - 2¹⁹ = 20430906733 is a prime.

It is a super-2 number, since 2×20431431021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20431431029) 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 15 ways as a sum of consecutive naturals, for example, 2783326 + ... + 2790656.

It is an arithmetic number, because the mean of its divisors is an integer number (1715534028).

Almost surely, 2^20431431021 is an apocalyptic number.

It is an amenable number.

20431431021 is a deficient number, since it is larger than the sum of its proper divisors (7017113427).

20431431021 is a wasteful number, since it uses less digits than its factorization.

20431431021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14252.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 20431431021 its reverse (12013413402), we get a palindrome (32444844423).

The spelling of 20431431021 in words is "twenty billion, four hundred thirty-one million, four hundred thirty-one thousand, twenty-one".