21021021120 has 672 divisors, whose sum is σ = 78640740864. Its totient is φ = 4715110400.

The previous prime is 21021021079. The next prime is 21021021149. The reversal of 21021021120 is 2112012012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21021021096 and 21021021105.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 296070685 + ... + 296070755.

It is an arithmetic number, because the mean of its divisors is an integer number (117024912).

Almost surely, 2^21021021120 is an apocalyptic number.

21021021120 is a gapful number since it is divisible by the number (20) 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 21021021120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39320370432).

21021021120 is an abundant number, since it is smaller than the sum of its proper divisors (57619719744).

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

21021021120 is a wasteful number, since it uses less digits than its factorization.

21021021120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21021021120 its reverse (2112012012), we get a palindrome (23133033132).

The spelling of 21021021120 in words is "twenty-one billion, twenty-one million, twenty-one thousand, one hundred twenty".