21020120000 has 420 divisors, whose sum is σ = 59205117048. Its totient is φ = 7392000000.

The previous prime is 21020119963. The next prime is 21020120041. The reversal of 21020120000 is 2102012.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21020120000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 208119950 + ... + 208120050.

Almost surely, 2^21020120000 is an apocalyptic number.

21020120000 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 21020120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29602558524).

21020120000 is an abundant number, since it is smaller than the sum of its proper divisors (38184997048).

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

21020120000 is a wasteful number, since it uses less digits than its factorization.

21020120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 21020120000 its reverse (2102012), we get a palindrome (21022222012).

21020120000 divided by its reverse (2102012) gives a 4-th power (10000 = 10⁴).

The spelling of 21020120000 in words is "twenty-one billion, twenty million, one hundred twenty thousand".