21231013424 has 20 divisors (see below), whose sum is σ = 41161795536. Its totient is φ = 10608614592.

The previous prime is 21231013423. The next prime is 21231013451. The reversal of 21231013424 is 42431013212.

It is a self number, because there is not a number n which added to its sum of digits gives 21231013424.

It is not an unprimeable number, because it can be changed into a prime (21231013423) 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, 405299 + ... + 454674.

Almost surely, 2^21231013424 is an apocalyptic number.

It is an amenable number.

21231013424 is a deficient number, since it is larger than the sum of its proper divisors (19930782112).

21231013424 is a wasteful number, since it uses less digits than its factorization.

21231013424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861524 (or 861518 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21231013424 its reverse (42431013212), we get a palindrome (63662026636).

The spelling of 21231013424 in words is "twenty-one billion, two hundred thirty-one million, thirteen thousand, four hundred twenty-four".