21431211344 has 10 divisors (see below), whose sum is σ = 41522972010. Its totient is φ = 10715605664.

The previous prime is 21431211343. The next prime is 21431211379. The reversal of 21431211344 is 44311213412.

It can be written as a sum of positive squares in only one way, i.e., 21407201344 + 24010000 = 146312^2 + 4900^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431211341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 669725339 + ... + 669725370.

It is an arithmetic number, because the mean of its divisors is an integer number (4152297201).

Almost surely, 2^21431211344 is an apocalyptic number.

It is an amenable number.

21431211344 is a deficient number, since it is larger than the sum of its proper divisors (20091760666).

21431211344 is a wasteful number, since it uses less digits than its factorization.

21431211344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1339450717 (or 1339450711 counting only the distinct ones).

The product of its digits is 2304, while the sum is 26.

Adding to 21431211344 its reverse (44311213412), we get a palindrome (65742424756).

The spelling of 21431211344 in words is "twenty-one billion, four hundred thirty-one million, two hundred eleven thousand, three hundred forty-four".