21001211000220 has 48 divisors (see below), whose sum is σ = 64149153602688. Its totient is φ = 5091202666560.

The previous prime is 21001211000219. The next prime is 21001211000221. The reversal of 21001211000220 is 2200011210012.

It is an interprime number because it is at equal distance from previous prime (21001211000219) and next prime (21001211000221).

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 = 21001211000196 and 21001211000205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001211000221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15910007674 + ... + 15910008993.

It is an arithmetic number, because the mean of its divisors is an integer number (1336440700056).

Almost surely, 2^{21001211000220} is an apocalyptic number.

21001211000220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001211000220 is an abundant number, since it is smaller than the sum of its proper divisors (43147942602468).

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

21001211000220 is a wasteful number, since it uses less digits than its factorization.

21001211000220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31820016690 (or 31820016688 counting only the distinct ones).

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

Adding to 21001211000220 its reverse (2200011210012), we get a palindrome (23201222210232).

The spelling of 21001211000220 in words is "twenty-one trillion, one billion, two hundred eleven million, two hundred twenty", and thus it is an aban number.