21020001220000 has 120 divisors (see below), whose sum is σ = 54754260181236. Its totient is φ = 7913412096000.

The previous prime is 21020001219989. The next prime is 21020001220007. The reversal of 21020001220000 is 2210002012.

It can be written as a sum of positive squares in 10 ways, for example, as 4437611886096 + 16582389333904 = 2106564^2 + 4072148^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21020001220007) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 30571767 + ... + 31251766.

Almost surely, 2^{21020001220000} is an apocalyptic number.

21020001220000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020001220000 is an abundant number, since it is smaller than the sum of its proper divisors (33734258961236).

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

21020001220000 is an equidigital number, since it uses as much as digits as its factorization.

21020001220000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61823580 (or 61823557 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21020001220000 its reverse (2210002012), we get a palindrome (21022211222012).

The spelling of 21020001220000 in words is "twenty-one trillion, twenty billion, one million, two hundred twenty thousand".