21431131403 has 16 divisors (see below), whose sum is σ = 24007734240. Its totient is φ = 18965836800.

The previous prime is 21431131387. The next prime is 21431131409. The reversal of 21431131403 is 30413113412.

It is a cyclic number.

It is not a de Polignac number, because 21431131403 - 2⁴ = 21431131387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21431131409) 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, 99548 + ... + 229721.

It is an arithmetic number, because the mean of its divisors is an integer number (1500483390).

Almost surely, 2^21431131403 is an apocalyptic number.

21431131403 is a deficient number, since it is larger than the sum of its proper divisors (2576602837).

21431131403 is a wasteful number, since it uses less digits than its factorization.

21431131403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329438.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21431131403 its reverse (30413113412), we get a palindrome (51844244815).

The spelling of 21431131403 in words is "twenty-one billion, four hundred thirty-one million, one hundred thirty-one thousand, four hundred three".