21431131017 has 32 divisors (see below), whose sum is σ = 30201790464. Its totient is φ = 13497504000.

The previous prime is 21431130991. The next prime is 21431131021. The reversal of 21431131017 is 71013113412.

It is not a de Polignac number, because 21431131017 - 2²⁷ = 21296913289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21431131217) 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 31 ways as a sum of consecutive naturals, for example, 1746658 + ... + 1758884.

It is an arithmetic number, because the mean of its divisors is an integer number (943805952).

Almost surely, 2^21431131017 is an apocalyptic number.

It is an amenable number.

21431131017 is a deficient number, since it is larger than the sum of its proper divisors (8770659447).

21431131017 is a wasteful number, since it uses less digits than its factorization.

21431131017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12709.

The product of its (nonzero) digits is 504, while the sum is 24.

Adding to 21431131017 its reverse (71013113412), we get a palindrome (92444244429).

The spelling of 21431131017 in words is "twenty-one billion, four hundred thirty-one million, one hundred thirty-one thousand, seventeen".