21002100201220 has 12 divisors (see below), whose sum is σ = 44104410422604. Its totient is φ = 8400840080480.

The previous prime is 21002100201217. The next prime is 21002100201223. The reversal of 21002100201220 is 2210200120012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21002100201217) and next prime (21002100201223).

It can be written as a sum of positive squares in 2 ways, for example, as 5923976302084 + 15078123899136 = 2433922^2 + 3883056^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21002100201220.

It is not an unprimeable number, because it can be changed into a prime (21002100201223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525052505011 + ... + 525052505050.

It is an arithmetic number, because the mean of its divisors is an integer number (3675367535217).

Almost surely, 2^{21002100201220} is an apocalyptic number.

21002100201220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002100201220 is an abundant number, since it is smaller than the sum of its proper divisors (23102310221384).

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

21002100201220 is a wasteful number, since it uses less digits than its factorization.

21002100201220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1050105010070 (or 1050105010068 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21002100201220 its reverse (2210200120012), we get a palindrome (23212300321232).

The spelling of 21002100201220 in words is "twenty-one trillion, two billion, one hundred million, two hundred one thousand, two hundred twenty".