21643131260 has 12 divisors (see below), whose sum is σ = 45450575688. Its totient is φ = 8657252496.

The previous prime is 21643131229. The next prime is 21643131269. The reversal of 21643131260 is 6213134612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21643131269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 541078262 + ... + 541078301.

It is an arithmetic number, because the mean of its divisors is an integer number (3787547974).

Almost surely, 2^21643131260 is an apocalyptic number.

21643131260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21643131260 is an abundant number, since it is smaller than the sum of its proper divisors (23807444428).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21643131260 is a wasteful number, since it uses less digits than its factorization.

21643131260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082156572 (or 1082156570 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

Adding to 21643131260 its reverse (6213134612), we get a palindrome (27856265872).

The spelling of 21643131260 in words is "twenty-one billion, six hundred forty-three million, one hundred thirty-one thousand, two hundred sixty".