21631343231 has 8 divisors (see below), whose sum is σ = 22784622720. Its totient is φ = 20479542552.

The previous prime is 21631343221. The next prime is 21631343243. The reversal of 21631343231 is 13234313612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21631343231 is a prime.

It is a super-2 number, since 2×21631343231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21631343194 and 21631343203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21631343221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 339605 + ... + 398238.

It is an arithmetic number, because the mean of its divisors is an integer number (2848077840).

Almost surely, 2^21631343231 is an apocalyptic number.

21631343231 is a deficient number, since it is larger than the sum of its proper divisors (1153279489).

21631343231 is a wasteful number, since it uses less digits than its factorization.

21631343231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 739405.

The product of its digits is 7776, while the sum is 29.

Adding to 21631343231 its reverse (13234313612), we get a palindrome (34865656843).

The spelling of 21631343231 in words is "twenty-one billion, six hundred thirty-one million, three hundred forty-three thousand, two hundred thirty-one".