21012443000 has 64 divisors (see below), whose sum is σ = 50864673600. Its totient is φ = 8115139200.

The previous prime is 21012442993. The next prime is 21012443009. The reversal of 21012443000 is 34421012.

It is a self number, because there is not a number n which added to its sum of digits gives 21012443000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012443009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 333284 + ... + 391283.

It is an arithmetic number, because the mean of its divisors is an integer number (794760525).

Almost surely, 2^21012443000 is an apocalyptic number.

21012443000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012443000 is an abundant number, since it is smaller than the sum of its proper divisors (29852230600).

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

21012443000 is a wasteful number, since it uses less digits than its factorization.

21012443000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724617 (or 724603 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21012443000 its reverse (34421012), we get a palindrome (21046864012).

The spelling of 21012443000 in words is "twenty-one billion, twelve million, four hundred forty-three thousand".