21021230120020 has 96 divisors (see below), whose sum is σ = 49114225714176. Its totient is φ = 7505132544000.

The previous prime is 21021230120003. The next prime is 21021230120021. The reversal of 21021230120020 is 2002103212012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21021230119976 and 21021230120003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021230120021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8737495 + ... + 10880545.

It is an arithmetic number, because the mean of its divisors is an integer number (511606517856).

Almost surely, 2^{21021230120020} is an apocalyptic number.

21021230120020 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 21021230120020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24557112857088).

21021230120020 is an abundant number, since it is smaller than the sum of its proper divisors (28092995594156).

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

21021230120020 is a wasteful number, since it uses less digits than its factorization.

21021230120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144321 (or 2144319 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21021230120020 its reverse (2002103212012), we get a palindrome (23023333332032).

The spelling of 21021230120020 in words is "twenty-one trillion, twenty-one billion, two hundred thirty million, one hundred twenty thousand, twenty".