21021201024 has 128 divisors (see below), whose sum is σ = 56401920000. Its totient is φ = 6936652800.

The previous prime is 21021201001. The next prime is 21021201043. The reversal of 21021201024 is 42010212012.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 21021200994 and 21021201012.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18262849 + ... + 18263999.

It is an arithmetic number, because the mean of its divisors is an integer number (440640000).

Almost surely, 2^21021201024 is an apocalyptic number.

21021201024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21021201024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28200960000).

21021201024 is an abundant number, since it is smaller than the sum of its proper divisors (35380718976).

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

21021201024 is a wasteful number, since it uses less digits than its factorization.

21021201024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606 (or 1594 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21021201024 its reverse (42010212012), we get a palindrome (63031413036).

The spelling of 21021201024 in words is "twenty-one billion, twenty-one million, two hundred one thousand, twenty-four".